1. Replace your old faucet. Is your old chrome faucet from the 80's? An inexpensive update is also water saving. Whether you have a widespread or vanity style (see below), you can go from dull to savvy styling with better function in about 20 minutes, often for under $100. Check out the Delta faucets at your local home improvement store.
3. Update your lighting. A simple switch of a bath light from one style to another is often enough to have a huge impact. A fresh new fixture with CFL or LED bulbs will give a new look with better lighting.
4. Replace all of your hardware. Change all of the knobs, pulls, towel bars and bath accessories for a new look. Don't have tools? Tape off everything and spray on a coat of Rustoleum that's meant for the surface (metal, ceramic, etc...) and enjoy a new color.
5. Create a new storage system. If your counter top is cluttered with bottles, add shelves over your toilet. A few baskets on the shelves, inside the cabinet, and even on the counter - if there is room - makes a huge difference.