As a writer for renovateyourworld.com, I rarely cite articles from Scientific American but this article entitled "How Room Designs Affect Your Work and Mood" is too good to pass up. This lengthy piece documents the state of research into using room design to "promote creativity, keep students focused and alert" and increase relaxation and social intimacy. One professor has found a link between ceiling height and the way we think (taller ceilings appear to encourage more abstract thought while shorter ceilings encourage more concrete thinking). There's a slew of scientific findings in the article. Read the entire piece to get some great ideas of how to improve your surroundings.