1. More bang for you buck.
The best thing about a small bathroom is that you have more room to spend since you do not have to buy more to fill up a larger space.
2. Stay away from dark walls.
Darker wall colors tend to make a space look smaller and closed in. Try to go towards lighter colors to open the bathroom up and make it brighter with pops of color throughout the room.
3. Glass shower doors.
Use glass shower doors to give the illusion of a bigger room because it would not be cutting off the bathroom in sections.
4. Contrast simple walls with a patterned floor.
Keeping the focus on the floor will draw attention away from how small the room and make the room seem more open. Also, continue the patterned floor into the shower to keep it from being closed off.
5. Lighting and Mirrors.
Mirrors will reflect whatever light enters the bathroom through the window(s) and cast it on other parts of the bathroom, making it look brighter. The bigger the mirrors, the better because it will take attention away from the small walls. If you do not have adequate window space, or no windows at all, make sure there is a ton of lighting in the bathroom to illuminate it!
6. Storage.
One of the best ways to avoid making your bathroom look smaller is to avoid clutter. Add opportunities for storage throughout the bathroom in your vanity, cabinets and shelving in spaces that otherwise would not have been used such as a small alcove.
7. Ditch the tub.
If you do not usually take baths, there is no need to have a tub that takes up space in your small bathroom when it will never be used.
8. Floating and/or small furniture.
Replacing your old vanity and cabinets with floating furniture, which is attached to the walls and have no legs, can make the room look bigger. Another idea would be to make all of the furniture in the bathroom smaller so they do not take walking space away from the area.