A list of (web) user interface design principles. They are all on a conceptual level, so good for high-level/big-picture work.

Some examples:

• Clarity is job #1
• Interfaces exist to enable interaction
• Conserve attention at all costs
• …
• Smart organization reduces cognitive load
• Highlight, don’t determine, with color
• …
• Existing problems are most valuable

A commenter on Hacker News added these even more general rules:

1. Respect your users
2. Respect their time
3. Respect that they are different from you

If you find yourself thinking “now I have to change it so stupid people can use it” then you will never make a UI worth a damn.