I have always had a notoriously difficult time trying to open my envelopes neatly. I aim to have them looking somewhat aesthetically pristine.
But, of course… as carefully as I try to work a pair of scissors or pen knife… I always end up with all kinds of horrible, devastating tears that leave the poor envelopes looking most battled and war-torn.
I have to open lots of envelopes (at work…) and I can only recommend a letter opener. I use a very basic one (I’ve paid less then 2 €), but it works like a charm.
I use a knive to open my letters, it’s one of my dearest items, since it’s made by my father, and he always encouraged me to write to different countries
I looked for a letter opener but couldn’t find one that I liked. Then I remembered my 40th birthday present - a replica woman’s knife (sorry i’m not an historian but my friend is very into the ancient history of England). It was incredibly sharp but paper has taken the edge down. That said it is still sharp. I’ve not given it any special care and after use it goes back into the handmade silver cardboard holder (she loves to recycle) that covers the blade and has done an excellent job of protecting my fingers. The blade and handle are a little over 6.5 inches long.
I think my friend made the cover from a bit of silver card she had (loves to recycle). Though it is not a letter opener it does a gread job and is a much loved part of my correspondence kit. I’m now waiting for the writing desk to go with it.
I use the most useless knife in my knife block: a razor sharp 20cm (8in) fillet knife. It has never filleted anything, but has opened 100’s of envelopes.
The right angle is the secret to a nice result. The angle should be as large as possible, e.g. 160-170 degrees, the knife or letter opener should be placed as flat as possible.
I switched to using a regular letter opener decades ago, because like you my envelopes ended up destroyed. The one time I shredded a check that was inside, convinced me to use letter openers. I’ve tried fancy ones, serrated edges, but am using a very plain one with a flat edge. A kid could poke itself, but not cut itself with mine, which works like a charm. Since they regulary disappear (mainly to the garage, though my husband swears he isn’t the one to move them), I’ve got three around the house at the main places mail gets opened.
If you’ve never used one, take a piece of scrap paper, fold it, and try using the letter opener. You’ll find that a certain angle works best (see up a few comments on the precise measurements).