[jyl]

Main things I do is
1. Keep wrists straight or a little droopy (i.e. palms closer to forearm), not cocked (back of hand closer to forearm). This can mean raising keyboard, or tilting it away from you. A low keyboard, tilted toward you, is the worst.
2. Same with mouse hand. A gel pad under mouse hand wrist helps.
3. Keep neck straight. Shouldn't have neck hunched over (monitor too low) or craned (monitor too high).
4. No reflections on computer screen. Close shades, move computer, or use polarizer.