Has this been asked somewhere before? 
I’d like to ask what kind of stamps you like to collect!
Is there a specific theme you adhere to or do you hoard any and all stamps?
Do you collect only new/mint/unused or do you prefer used/canceled?
Do you take them off of letters? Do you cut around the paper?
Do you prefer to collect newly issued stamps or the oldest you can find?
I’m new to stamps so I would love to see your prized stamps or hear about your themed collection (or random hoard!)
I’m happy that you started having interest on stamps! The stamp world is a magic one.
So your question is an interesting one. I’ve been collecting stamps since some years now, and it has been not a long time since I really decided what to collect. I think it is better to chose what to collect and not just to keep every stamp you find. That is for two reasons: first, having some spare stamps helps when you are organizing swaps; second, I think that keeping all the stamps does not make up a collection, but just an obsessive compulsive accumulation. 
As I am Italian, I am collecting Italian stamps, but just up to the year 2000. Why so? Mostly because newer stamps are more expensive to obtain. I prefer used stamps for two reasons: first, they’re more cheap; second, I think a stamp with a postmark has much more things to tell you than just a new stamp alone. I may explore for example the journey it went through. I usually take them off paper, which is quite incoherent with what I just wrote about the journey of the stamp. I just think that off paper stamps look more neat in a collection. Anyway, when a find a special postmark, I make sure to keep it as well, so I cut around the paper. I keep them on paper as well when there happens to be self adhesive stamps. I try to soak them on water, but if I see it doesn’t work I leave them on the paper, cutting around the postmark if it is an interesting one, else cutting close to the stamp edge. But as I collect only pre-2000 stamps, there are very few self adhesive ones. (lucky me 
)
I find it really interesting to study the history of my country through stamps. I am particularly happy about my pre-1900 stamps, when Italy still was a kingdom, and the stamps during the fascist era. Those years are a dark chapter in the history of Italy, and having the possibility to touch with hand the propaganda stamps or the celebrative stamps really helps me to dive into those sad years.
I’m collecting a particular topic as well, which is flowers on stamps. I started doing this because the just look really nice and colorful to me. I started accumulating pretty much every flower stamp, but right now I’m considering to make my collection more precise (remember the “obsessive compulsive accumulation” statement? 
), for example by keeping only those stamps that look more “botanical”, so that have the Latin name of the flowers as well, and not just the picture of the flower. In this collection I am not strictly considering only used stamps. I just don’t care much. Obviously I prefer them used, for the reasons I stated about the Italian stamps, but if there happens to be a new emission of flowers on stamps and I manage a swap with someone living in the country of emission, I prefer to ask them to put the stamps new inside an envelope. I’m really scared that they could get damaged during the trip. So another thing which is different between this collection and the Italian one, is that with the flower stamps I try to keep up on date, so I constantly check whether there are new emissions and then try to arrange a swap. Let’s say Austria has new flower stamps: I just look at the Austrian postcrossers, browse them by the most active or the last seen on the site, and, if they accept direct swaps, I contact them. For the flower stamps, as I collect the more recent ones as well, I happen to have many FDCs and minisheets. But again, in this case seeing them beside the used ones does not make me uncomfortable.
I have been thinking about since some time about starting an airplane collection as well, because aviation is my passion and I would really like to study this topic through stamps. But I just started, so I have no more than 50 airplane stamps I think.
I hope I helped you! Have fun!
I don’t collect stamps. But the variety of stamps used on my received postcards make me happy.
From time to time I remove used stamps from my everyday mail just to stick them on postcards going to stamp collectors/lovers.
Hey! Welcome to the world of Philately! 
I used to hoard all stamps until last year when I chose 3 themes to collect.
I collect both used and mint stamps of the following themes: Gastronomy, Coins, and Cargo ships. I chose these themes as they were a part of what I do and what I like. I like foods from different countries which led me to choose gastronomy as one of my themes. I also collect coins, which I decided to implement in my stamps. As for Cargo ships, I am pursuing a career in marine engineering and that is why I chose it as another one of my themes.
I also collect all Japanese stamps in used condition. I think they’re really simple yet beautiful stamps. Of course, I am not interested in the more recent issues of Japan as they are difficult to find in used condition. They’re expensive in mint condition too.
I take stamps off the envelope if the envelope’s not too pretty to be cut. Else, I cut off the stamp with the postmark if its a nice and legible one. If not, just the stamp.
I think my post has a lot in common with @Tox97 's I guess that’s the way it is for most collectors.
I’d be glad to share some pics of stamps from my collection. I’ll do that in some time 
Happy collecting! Take care!
I collect flowers, butterflies, some Great Britain, and assorted stamps that catch my eye. I love beautiful stamps in series. I collect some vintage stamps.
I collect used but when a duplicate comes along without cancellation marks, I put it my my collection instead. Mint is nice but I can’t always swap mint for mint.
Some glimpses of my collection:
I am really on the lowest hobby level with stamp collecting, but after testing out a bit and seeing what I like, I settled to collect stamps with horses or any theme related to horses, famous women and European Union (along any other peaceful treaty). I am also kind of collecting Norden stamps and all kind of stamps from Nordic countries, but I haven’t yet made final decision about it. On other hand, I feel like it will be funnier to focus only on these couple of themed, but then also it would be more to do if I add countries in it too. I guess I will just keep trading and seeing what happens…
Now and then I find nice looking stamps from other themes and countries too, and try to find the whole series. That is more and less random, depending on what I happen to stumble upon. I have also got few stamps from interesting time periods or stories behind them. Those are included on special place on my collection.
When I first started I had no idea what I want to collect so I hoarded bit of this and that, getting old collections from relatives and buying couple of “surprise boxes” from old collectors. Once it became clear what I am looking for, I was left with lots of stamps I am not going to keep. I do trade them now and then when I have time to organize trades.
I prefer to collect used stamps. I just feel like it is better when the stamp has already “done its’ job”, but I do have some mint stamps too and even some that has been canceled without being used as postage.
So far I have only once bough a mint single stamp specifically only for my collection, without it being part of any surprise bag or bag of cuts from envelopes, and that was the Austrian Brexit stamp. I am not one to do auctions or go on hunt to find specific stamps, but that was something I knew I should get and it was on sale with the postage price.
almost ALL Spain stamps especially the monarch stamps. Not necessarily the basic ones with Felipe VI. The old ones too. Some with the peseta values on them
@Tox97 Wow! Your collecting sounds so fun. Doesn’t sipping stamps in water hurt them? Do you soak them overnight or just dab them with water? Do they just dry out?
@vishnurm19 Ooh I would love to see your collections!
I also love Japanese stamps they look gorgeous.
Asia in general has lovely stamps in my limited experiences of seeing them.
@DianeM wow I really loved seeing these, thank you so much for sharing. I like how you loosely organized the flowers by color!
@Kompis-Ninna horses sounds like a really cool collection to grow. Yknow now that you’ve said countries maybe it would be cool to have some kinda map and get a stamp from each country in that area 
That would probably be really hard tho. Haha.
@princeofasturias monarch stamps? Like monarchs in general or just Spain’s? That sounds really interesting
Thank you everyone for answering I love hearing about people’s collections 
i have a big collection as i have been collecting since childhood 
i try to limit my collections since to my favorite themes: cat, elephant, food, zodiac, heart/love, cartoon/comic …but i also have big flora and fauna collections 
also a big japan collection 
i prefer postally used stamps but do have some mint and cto (postmarked but not actually used)
How does this happen? Do you go to the post office and ask for postmark? That sounds cool
well that can be done too but mostly this cto refers to those stamps that are sold especially to children, stamps from exotic countries, in cheap packages maybe someone expert philatelist can explain better what is cto? cto are not appreciated by most stamp collectors. i also think they often seem like pictures and not real postage stamps…
I don’t…yet? Lately I started to think seriously about this because I’ve received some awesome Star Trek stamps from the USA over the years and recently I came across the new Star Trek Stamps from the UK. I have some postcards so I thought it would be nice to collect every mail thing Star Trek related, including stamps. 
We’ll see.
I collect stamps because it gives me the opportunity to have thousands of little artworks that I can arrange and re-arrange for fun. I like used stamps the best, because they have a history.
I mostly collect by themes, but I also have a ton sorted by country.
I am by no means a completionist, I just like to make little “exhibitions” in my stamp albums.
Here are some examples:
As a biologist, i like to arrange my flora and fauna stamps phylogenically (=by relatedness). However, visual similarity often wins over “biological correctness”
If I like a certain theme or style that re-appears in different stamps, I make a collection
Often, I find stamps that just look nice together:
And even when I group the stamps by country, I can’t help but sort them by color and/or theme
@mingshu Thank you for explaining, I looked some up and those are really nice, the cto
@alter3ch0 a Star Trek collection sounds awesome, do you think you will include space themes?
@bom_dia definitely a new world for both of us, although I’m not collecting yet, haha! I love what you have so far.
Like you I am wondering how you all get these stamps off of mail? Usually when I receive mail the stamps are very stuck, is there a trick?
@metlodyt Wowww. Thank you for sharing, oh my.
Visually this is so cool and impressive to me.
I tend to organize stuff chronologically, but I think if I ever collect stamps I will be grouping them together like this.
I loved the snow drops, that is my favorite flower.
Also I found it hilarious the ram? In the blueberries! 
Thank you @Sleep! I once joined a philately club, and they all laughed at me for not sorting my stamps in “the proper way”.
In my mind, he ate so many blueberries that he turned blue himself!
I cut off the little paper square containing the stamp (or actually, most of my stamps I buy by weight as “cut-offs”), then i put them in hot water (not hotter than you can have your hand in it), and leave them for a few minutes before i carefully start to separate paper and pictures. I leave them to air dry on some paper towels, and when they are almost dry, I put them in a special drying book (or just between paper towels in a normal book) to be pressed flat.
This works with 99% of stamps, but sometimes self-adhesive stamps are very difficult.
Ah so we have a tip from @metlodyt hot water.
Maybe if you try hot water it will be easier?
I think visual aesthetic is a nice way to organize your collection, it’s impressive once you have many!
Sometime hot water does help, but other times the stamp still stick. In these cases I carefully peel and destroy the paper, taking off little pieces until only the stamp is left. This is not a great solution though. I often end up with stamps that are either very sticky on the back, or very thin because part of them came off with the paper.
I have done some research, and some people recommend using different chemical solvents. I don’t really want to try it, since such things are not nice to work with, and you risk destroying the stamp completely if you use the wrong solvent.
Your ad hoc taxonomy is more compelling than anything official 
What do you do if the stamp from your favourite collection came with the nice postcard? It is always a problem for me. Do you cut the postcard?
I don’t. Sometimes i kinda want to. but i know that there are many copies of the stamp out there, and the postcard+stamp+message is completely unique. so the whole seems more valuable to me than the parts.
