What I know in Pokemon GBA Rom hacking:
Mapping, Scripting, Palette editing, Tile Editing.
I haven't done any hacking in a while, thus my knowledge has decreased, but I still remember the the main things to an extent.
I have plans on reviewing different Pokemon hacks in the future.
If you want to battle or trade with me on Pokemon White (And W2 in the future), tell me. We may be able to work something out.