There are plenty of fun Halloween costumes for women, but sometimes you just want to dress up with your best friend. If you're feeling a bit nostalgic this year, we suggest looking to Mary-Kate and Ashley Olsen for inspiration. With tons of home videos and TV shows under their belt, the possibilities for impersonating the twins are practically endless. So if you ever wanted to be them when you were younger, here's the perfect opportunity to live out your childhood fantasy.