Early on I was kind of chided by a few vets for using two hands, because I'm fairly tall. Especially around younger kids. Since then, I've done it with one hand, basically squeezing fingers and thumb together when my arm becomes fully extended (have to stop doing that). Always have to remember to get the right balance of thumb and finger pressure or, sure enough, that 45-degree-angle thing could take over.
Going to stand under a hoop and practice from now on.