I never pre-wash.
I spool the film, put it in the tank, then..
1) Develop - I use the massive dev chart over at digital truth (if you have an ipod touch or iphone you can get the massive dev chart app for 6.00 which also acts as a timer)
2) Stop Bath
3) Fix
4) Hypo Clear
5) Water Wash under running water for about 6-7 mins just to be sure
6) Photoflo
7) Hang to dry.
I hardly ever have any problems with my negatives.
One other tip, if you are using a patterson tank, I usually either try to wait until I have 2 35mm rolls and develop them both at the same time or if I really need a roll developed, like on a deadline or something, I put an empty roll in on top of the 35mm roll so I am sure it is all the way to the bottom and the chemistry will adequately cover it.