When I rollerset, I use a good leave-in conditioner (right now Lacio Lacio) and serum (Chi silk infusion, Paul Mitchell, or even my Morrocan Oil). I also use the ponytail method with rubberbands (I was using ouchless bands by Goody, but since they were a little thicker, my roots had a harder time drying straight). Also, I use two rollers for each ponytail, regardless of the size. I also dry under cool, for about a hour, switch to hot, then back to cool or airdry. This has given me the best results with straight roots and frizzless hair. I can rock my set for a few days before I was again (only because I want to now, not because of the awful humidity in Florida).