genejockey 

I agree with finding a descent you can get familiar with and doing it repeatedly. There's one here that I do whenever I climb, it's about 3 miles with 6% gradient. The lanes are wide, the surface is mostly good, most of the turns are sweepers, with only one or two well-marked hairpins. Because it's a TERRIBLE road to climb - too much uphill traffic - almost nobody ever climbs it, which means the cars on the opposite side all STAY on the opposite side, and you don't have to worry about taking up the entire lane. and because it's pretty twisty for a car, you're mostly going about the same speed as cars go, so you don't get them lining up behind you.

Checking my most recent descent, I averaged 27 mph down it, with a max of 32. That's even with my wussy descending, where I actually yell at myself to let off the brakes. One thing I've noticed is that the bike feel unsteady in a turn is almost invariably my own failure to commit, not really putting my weight onto the outside pedal and the inside handlebar, and if I do, the bike stabilizes and I carve the corner. So, descents for me turn out to be a battle with myself.