I don't use anything typically. Friends use Chamois Butt'r.

I discovered a while ago that I can tilt my seat ever so slightly forward and it changes everything. It causes me to very slightly slide forward --which I adjust frequently while riding. It may sound weird that I have to keep doing a mini-scoot a half inch backward --but it seems to effectively vary my position just enough to keep me from irritating a fixed spot on the butt or crotch. I can ride all day like that with no irritations.