I do low speed high heat. It makes my hair curl up nicely and gives me the least amount of frizz at least on this particular hair dryer.
I move my dryer around a lot I just don't manhandle my hair with it. Once my gel starts to harden I try not to touch my hair with it as much and at oh 70-80% dry I stop using the hair dryer and air dry for a bit then at 90-95% dry I scrunch the crunch out and let it air dry the rest of the way.
Unless I use a super stiff gel or rake a lot I always get big curls and waves.