Take the time to figure out what tactics work for you and your site. Don't be close minded and always be willing to try something new. Of course there are things that work well and stick with them. But always test and research.
Consider various sources of income for your sites. Adsense is great, but explore CPM, CPA and CoRegistration as a source of income as well. You may be limiting your earning potential if you don't.
oh... and .... sign up to Affiliateer.com
.... that last line wasn't blatant advertising... just trying to keep this post long, in an effort to keep the thread long. Cheers!