You may or may not believe in Feng Shui but sometimes it just makes sense. Here are some things I kept in mind when I rearranged my office:
Don't sit in line with the door because you'll be in the path of negative energy. Also, try not to sit facing stairs, storage rooms, or closets. (I'm not totally sure what this means but I thought I'd try it.)
Definitely don't have your back to the door while your working. It said to be symbolically turning your back on business or opportunities that may be approaching. (I believe in unconscious symbols so I went with this one too.)
Try to have a good balance of yin and yang when decorating: light and dark colors, soft and hard surfaces, smooth and ruff textures. (loved this one! So many offices I've worked in would have been more tolerable with this in mind.)
If your interested in the rest you can look up on the super Zen internet like I did. Enjoy!