I use 6-10 reps for squats. 6 reps for 4 sets, or 10 reps for 3 sets, alternating workout. sometimes I start with leg ress for 20 reps, then squat with 10 reps. I always start with 4 x 20 reps on leg ext. I use the typical routine.., extensions, squats, leg press, leg curls, sld, calves. on the week I deadlift heavy, I start with leg press, squat and leg curl only, no SLD. occasionally I do 100 rep rest pause on squats with 225lbs. first set is mendatory 50 reps, then finish the rest in 2-3 sets(this seemed to work very well for shock growth). I also do lunges occasionally with decent weights(225) for sets of 6, to challenge my hip stability.