Some images are hazy when left to memory, you get the idea of what things might look like but you leave out some of the details. In drawing, especially in costumes, it's those details that really bring things to life. A little research is not only a way to improve your drawings but is usually alot of fun to learn from.
When I was looking up details for the Playboy Bunny outfit for this series of posts, there were alot of little things I knew were there but were previously drawing completely wrong. A little schooling is totally worth it!
I gotta say bunny ears may be the trickiest part to draw. Keeping the ear shapes while they curve takes a little practice, but breaking it down to basics is a good first step. I've got some work to do here but I'll keep at it :-)