For the most part, I start every table raising 4BB+1BB/limper, max 8BB pre-flop. I'll keep this strategy for the entire session at a standard table with mostly 20/10s where I want to isolate.

That being said, poker is not a static game. I always adjust my pre-flop play to the table after about 30 hands. With 2-3 stations, I want to keep my PF raise within their calling range. Sometimes it's 2BB, others it's 8BB. It's whatever it takes to get them to Valuetown.

I also think that your PF raising size isn't nearly as important as the hands you are raising. Sometimes I'll shown down with mid pair when I know I'm beat because it gets the villans opening up my range. If my percieved range is greater than my actual range for most hands, I can get more action on 4th and 5th street.