I dont deadlift frequently at all, I should really deadlift much more. A year ago I severely strained my back though and have been kinda skeptical to go heavy. The most I've done recently was 200lbs for 20 reps. When I do deadlift, I deadlift light and usually dont change the weight. I'll do a warm up with the bar, then with 135, throw 200 even on there and do 3-4 sets of 20.
I should probably do hyperextensions more, my lower back is rarely trained.