We made a witch costume tutu for my little girl yesterday, it added the extra flare we looking for. Tutu's are an easy cheap costume idea and the possibilities are endless...
here are some of my favorites
here are some of my favorites

Baby Mermaid...oh my heck I'm in love!

Little Red Riding Hood
Oh what an adorable child...and the costume's pretty cute too.

This is one of my all time favorites...must try
Peacock

Scare Crow

Belle

Baby Witch
Mirida

Cowgirl

Snow White
If you change up the colors and accessories you could make just about any princess.
Pumpkin
Clown


Audrey Hepburn
Butterfly

Bumble Bee

Super Heroes

Little Lady Bug
Hopefully this helps you come up with some ideas, even if you need a last minute costume these are really easy to throw together, we did ours in about an hour.