Erik D. Kennedy, 7 Rules for Creating Gorgeous UI (Part 1):
This is the Krav Maga of screens.
Definitely worth reading, especially if youâ€™re one of those folks that tends to think that great design only comes from this small subset of â€œtalentedâ€ people. Nope: there are a few basic rules, and you can learn them. (And hereâ€™s part two.)