The three that resonated most with me are:
Tame Complexity; don’t simplify
The law of conservation of complexity states that applications have inherent complexity that needs to be dealt with in product development or user interaction. Complexity provides power, but don’t make people deal with a complex interface.
Make non-arbitrary design decisions
Design with purpose. You should have a rationale for every design decision you make. “Because its cool,” “Because it’s trendy,” “Because I wanted to,” “Because it’s a best practice” is not good enough.
Understand and play with emotion
Human emotions are at the core of perception and interaction. As a UX designer you must understand emotions and how to design for emotion.
Anyhow, tuck into the slideshare below, and be sure to check out the A-Z of user experience design principles, which I collated last summer.
Pretty much on the money, I’d say, but do leave a comment below if you think Erik missed anything…