Costumes

I am quite possibly the worst person at picking out Hallowe'en costumes. When I was younger my sister would always be the one excited in September about getting a costume and my parents would just end up getting two of whatever she wanted and I'd wear the same thing. I normally hated the twins-must-dress-alike thing but I just went with it for Hallowe'en.

This yeah, however, I want to give it a shot. Only I don't really know where to go or what to do. Does anybody have any tips or help they can offer me? Any advice would be greatly appreciated. :)