Jonathan Snook is an accomplished programmer, and while he doesn’t consider himself a designer, his designs are something I am very envious of.
He lays out some tips that he tries to keep in mind when doing a design:
1. Make it bigger.
2. Make it closer to the top of the page.
3. Make it a different colour.
4. Use a different font.
5. Give it breathing room.
Check out the full post, including his thoughts behind each point at his blog, Snook.ca.