The latest definitive stamps released in Ukraine (10th series, “Pysanky”) show Easter eggs from various regions of Ukraine.
First issue in the 2010ths
2017-2022: 9th series “Coats of arms of cities, towns and villages of Ukraine”
2012-2016: 8th series “Leaves”
First issue in the 2000ths
2007-2012: 7th series “Common items”
That one has reprinted value - from 0,01 UAH to 2 UAH
2001/2002-2006: 5th and 6th series “Flowers”
This stamp block is called the “5th and 6th series of definitive stamps” and I’m not sure what is so different between the two.
First issue in the 1990ths
1995-2006: 4th series “City transport”
This series is the smallest of all. It features only 3 stamp types.
1993-1993/1994-2001 3rd and 2nd series "Ethnographic stories «Ancient Ukraine»
We’re getting closer and closer to the formation of modern Ukrposhta.
3rd series was a continuation of 2nd series. For some stamps small, but very important in the economic context of this time change - the value of the stamp was no longer displayed as number. Inflation of the Ukrainian currency had reached in 1994 year state where smallest karbovanets banknote in use was 100, and a year later 1000 krb. In the new series value of the stamp wasn’t fixed and stamps were usable after the 1996 transition from karbovanets to modern hryvnia.
2nd series - stamp with value 100 krb.
3rd series - stamp with the letter “Є” (“Ye”)
16.05.1992 - 1st series of postal stamps in independent Ukraine - “Allegory «Young Ukraine»”
The drawing made by Heorhii Narbut originally was used for a stamp with a value of 0,3 Ukrainian People’s Republic’s hryvnia (18.06.1918). Notably, these stamps weren’t used only for postal services, but also instead of coins.
There is much more to tell about the postal stamps of Ukraine before and after independence from the USSR, but I would recommend you to look at Ukrainian Wikipedia’s article about that: Direct link, Translated to English with Google.