i think it matters a lot what's at the bottom of the hill!
if the road or trail goes on without too hairy of a turn i crouch, possibly rest my upper-body weight with my elbows against my legs, and enjoy the break.
it's a bit different if there's cross-traffic or a hard turn at the bottom of the hill, or if the hill is so steep that you'd get to an uncontrollable speed. it's always easier to stay at a speed you can live with instead of trying to recover from too fast. if the road is wide enough you can traverse from side to side like you'd do on skis or a snowboard and turn uphill at the end of each traversal. if that's not possible, brake as much as you need to to stay safe. if it's a long hill, start braking early. and if you're braking t-stop fashion, you might alternate feet so as wear your wheels evenly.
i think most everyone eventually finds themselves on a hill that is too steep to be skated safely. when that happens, look for the best place to get off or lay it down. grass is much softer than concrete!