i recently got a wacom tablet so i just drew some things in AS- mostly the building bkgrnds and just did the base flat color
the alot of the other stuff i painted the lineart in gimp
since the painting was in gimp- i did alot of fills with textures then made another layer and multiplied it
Then alot of the grass and trees were done with custom brushes in gimp too and
Sometimes for rocks and other things i'd just make a bunch of transparency layers with different texture fills and some custom brushes- almost all of them are like 5 to 7 layers of different things
I personally like the super hairlines so all my stuff and characters are usually like this