Simple tips:
1)Make sure you can see doors and windows from where you sit
2) In a busy office avoid being near entrances unless it's your job to greet people - otherwise you will be distracted whenever someone comes in
3) If you share your space with others, have agreements about where things go and what you won't tolerate
4) Use your instincts rather than fashion to guide your choice of decor. Aim for colours that are sympathetic to the purpose of the room
5) Eliminate reflections and glare from TV and computer screens
6)Make sure you have enough insurance cover
7) Replace poorly designed tools, furniture and equipment - if they don't do the job efficiently and are not a pleasure to use they will cause irritation
8)Invest in ergonomically designed seating and ensure your desk and workstation are correctly adjusted
9) If something intrudes on your concentration settle yourself about it consciously or your body's systems will continue to wonder about it
10) Take frequent breaks and move around
11)Make sure there are some pleasing natural things around you - especially if you can't see much outside
12) Use an answering machine to limit calls to when you want to take them
source:
http://www.ecopraxis.co.uk/selfhelp/stress.htm