I think the characters from Madoka Magica are still rather popular, so that could be an idea.
Kuroko no Basket is pretty popular now too from what I can tell, so Riko or Momoi might be well received.
The anime [K] is still new and also popular from what I can tell, and Neko, Anna Kushina and Seri Awashima are the most notable females in that.^^
Otherwise your guidelines are really vague. Do you care if you match the character appearance wise? Does the outfit have to be simple or cover you up a lot or something? Any genres you like etc?
| Animuc | ChisaiiCon | DoKoMi |
~ ♥ ~
| Wendy Corduroy - 85%|
| teenage!Uta - 70%| Sho Hinakawa - 55%|
| Firecracker Jinx - 20%|
~ ♥ ~
| Facebook | Tumblr | WorldCosplay |