Here's a neat trick to store your matching outfits together without needing to build a bigger wardrobe. Household weblog Idea in a Bottle demonstrates how you can create double hangers using the tab off a beverage can. Once you pop the tab t off, slide the hanger through one hole and use the other hole to support an additional hanger.
Obviously, you'll want to use this tip on sturdier hangers. This way, you can keep your specific matched sets together (e.g. uniforms) to save time when getting dressed.