Write a clear and comprehensive privacy policy. People may not choose to believe it, but having one is better than not having one. Ours is here . Set down delivery guidelines and stick to them. With TidBITS, that has meant publishing on exactly the same day every week for 9 years, and for the last 5 or 6 years, sticking to a self-imposed 30,000, character limit.
People trust regularity.
Strive for professionalism and quality at all times. This may be easier for us than for many people, since we're professional writers and editors, but it is worth the effort. Respect your users. People aren't dumb, and if you respond quickly to comments and suggestions with explanations of why you might or might not implement them, that goes a long way toward helping your reputation. I won't pretend that these suggestions are all that easy to implement, since for the most part, they require changes on the part of people, not pages.