Of all the problem spots in a small apartment, a small bathroom is one of the toughest, because there are so many things you need to fit into so little square footage. Here, as in the rest of the house, wall-mounted shelves can be a real lifesaver. No matter the size of your bathroom, there's probably a spot where you can squeeze in a shelf or two, and provide a spot for towels or TP or what have you. Here are some of my favorite ideas.
Got a corner? Take a cue from the bathroom above, from Southern Living, and squeeze in some corner shelves. Don't forget to look above your head, as the best spot for corner shelves may be up high.
One particularly handy place to add a shelf is right above the sink (like Ashley did in her Chicago apartment). This is a great place to store toiletries you use often, and takes some of the pressure off of a small sink area.
The space above the toilet is ripe for shelving. Concealing things in baskets (as seen here in a bathroom from My Fabuless Life) is a great way to control clutter.
If your toilet is next to a wall, this could also be a great spot for shelving, as seen here in a very organized bathroom from The Order Obsessed.
Even in bathrooms where the space between the toilet and the wall doesn't allow for deeper shelves, you can add a shallower shelf (or even a picture ledge, like in Chris' Chicago studio) for toilet paper or toiletries.
Especially if your ceilings are taller, the space above the door is practically begging to be turned into storage (as seen here in a bathroom from IKEA). If you're not particularly tall, you may need a step ladder for this one.
The last place to add a shelf isn't on the wall at all, but actually inside your vanity. As seen on House Mix Blog, adding a shelf is a great way to tame a cluttered vanity cabinet, and make your small space work just a little harder.