I would have to agree with Romeo on this one. I spent a year trimming up on my autos before I saw this sight, and after much studying I decided to just let her do her thing. The ONLY time I take the scissors to her before harvest day is if some bottom leaves turn full yellow/crunchy and are no longer providing benefit to the plant. If you go and look at some of the killer grow journals in here, right before harvest often all the fan leaves have lost their color. The plant will actually use up the stored energy in the fan leaves toward the end of her life, so everything you leave there for her will help out!
Cheers, L4