Just came across a post by Ev Williams with some rules to live by that I thought were pretty useful--a couple of them are the following:

• At any given time, focus on as few things as possible.
• Always start simply.
• There are always more opportunties and ideas.
• Good people want to kick ass. Join forces with good people and let them.
• Take the long view.
• There are few things more important than where you put your attention.
• Measure. Machines are better than humans at knowing what is really going on inside machines and can even be helpful in figuring out what's going on inside humans. Make them tell you and make better decisions.
• Pretty much everything is about user experience.

(Susan sez: I recognize it's partly my perfectionism that consistently draws me to these kinds of lists, but it's also my ability to learn from other people--and this is good advice.)