(click on bolded text for link) Installing a mirror and light to your closet not only makes it more functional but look super chic as well. You can get a full length mirror almost anywhere for about $20. My brother just purchased several from Ikea and I was really impressed with the minimal mounting hardware it came with. Don't forget to install a hook above it.
As for lighting, if you own your place it may be worth having a licensed electrician install one. If you rent, hang one yourself. I prefer plug in lights but if that's not an option for you, use LED battery operated ones so you don't have to change the batteries so often. In the closet above I used a cord kit with a small paper lantern. By placing a small hook on the ceiling then one in the corner (closest to the door) I guided the cord under the door to the nearest outlet.
Adding a thin carpet to the floor of your closet adds the final touch (see pic in shoe storage post). It also helps keep the dust bunnies at bay.