Normally I'll just leave the reverse search engine here and let you go nuts but some disclaimer first.
1) THIS DOESN'T ALWAYS WORK. It's still best to browse websites and find artist yourselves (or ask around).
2) You're might see a lot of porn/disturbing thing thumbnails even thought you don't want to, it's just that so much of the images in the search engine is porn, is bound to happen. Use at your own risk and don't come after me with pitchforks when you get scarred for life, please.
Alright with that out of the way:
Saucenao:
If you don't find a perfect match, prepare for a lot of weird hentai <3.
This engine isn't perfect but I still say it's pretty useful.
Finds images from:
H- Magazines
H- Anime
H- Game CGs
Doujinshi DB (useful <3)
Pixiv
etc...
Tineye:
Doesn't always search deviantart though for some strange twisted reason the ones that show up are usually the stolen works. Though that's not always the case, for example works on Kl-chan's deviantart shows up fine. So maybe it has something to do with popularity, still not sure why the stolen works were shown though.
iqdb:
Good for images that people upload on to image boards.
Basically if you know http://e-shuushuu.net/ then you should know the images that this website finds.
Google reverse image search: