1.the background??well depents on the subject of your work...if it's a devil (for example) use dark colors (also depents on what kind of devil) so you can use black-red
but also combinations like black-green black-skyblue,so the devil looks like he's toxic or something
for things like fairies and elfs... use soft colors. most of the time fairies are drawn in woods, try some combinations in green- soft yellow- skyblue and orange. a bit brown would finish the drawing in my opinion
try not to use random colors,but create new combinations, people will love that, i guess

2.beautiful gallery you have here!!!!!
3.well, good luck with your backgrounds
remember, this was only a tip, i'm not saying you must use it...

visit my gallery if you like, but you won't find any backgrounds haha i'm not done with my drawings... i think i will use this tip for myself

well bye. x Galadriël