After thinking about the design of the rest of your home so that you can incorporate some of the same design elements, then ask yourself a few questions.... What colors make you feel the most relaxed? Is it pale gray bedding like this bedroom via Little Gray Paint Company? If you're often cold, make sure you have plenty of throws handy. Do you need a small desk to make balancing your checkbook a little easier? What about lighting....how much or how little do you need?
Lastly, white floors go a long way in helping a space feel calm and serene. It opens up the space and makes it feel clean.