Going back to 2008 with 2.4ish...
I got my Wacom Tablet in early '08 and have been having a blast since (okay, for a while there was a lot of frustration trying to get the Wacom to work with Ubuntu 8.04... So I used Windows XP, then there was trouble getting the tablet to work with X11 on Mac... So I stuck to Windows for a bit... Then I found out how to configure X11 to use my tablet and so today most of my stuff is don in OSX).
Being a USAF veteran, I love my A-10 Warthogs:
This was my best back in '08 and '09. Nothing but default brushes, and bunch of layers. No layer mode modifications or anything else like that...
Some of my early work doing some Concept Art Daily Sketch Group subjects (another great forum for artists...):
I'll have to dig up some more recent work using 2.6, and get around to doing some stuff with 2.8! Needless to say, learning the layer modes, and custom brushes (thanks especially to the folks who worked on the GPS!) things have only improved!