I love Salerm 21 for my rollersets. It only takes a small amount. Anything excessive and it seems to dull my hair. A little dab will do ya. NTM Serum and cream are also good products. Sometimes I will put the Salerm 21 or NTM in my spray bottle so that when I re-wet, a little more is applied.
I have found that technique also makes a huge difference in the appearance of the roller set. I have had two different roller set results using the same leave-in, but with with varying degrees of tension used to really pull the roller tight. The tighter, the better.
As an aside, I went to the Wal-Mart salon near me and the stylist put in the 21 like I asked. Then before I could say anything she started pumping this foam ALL over my head. My hair was a hot, sticky mess when she was done even with sitting under the dryer for 1 hour. She then proceeded to attempt a blow-out with lots of breaks to spray Dudley's sheen spray. I was so disgusted I just paid the $14 and never went back. The product does not make the roller set.