It's weird but I lie on my side and comb and tug my hair as flat to my head as possible against the direction of growth, especially around my neck, ear, and temple, where the growth direction is most opinionated. Usually I comb it with my fingers, but sometimes I use a pick or brush. It's careful work and I try to fall asleep with it like that.

Edit: I've wondered if other people do this, because it feels so natural to me, but I've never heard anyone describe it.