I recently came across a web site that details the 11 Rules of Writing. Some of this stuff is common knowledge, but I find it is helpful to look at this now and again. I know I often fall victim to #10: Use the active voice unless you specifically need to use the passive. The nice thing about this site is that it gives examples of the wrong way to do things and also examples of the correct way to do things. Of course as they say, rules are meant to be broken.