regular squats: warm up then 7 by 7 or 5 by 5
leg curls: 8 sets, start with the highest weight you can handle for 8 reps with a pause at the top, keep on dropping weight in subsequent sets but keep the reps in the 5-7 range
lounges: 2 sets, 25 steps for each leg (50 steps total)
note: you can throw in 3 sets of leg presses after the leg curls if you have enough energy, keep reps in the 20+ range
or, if you are really wired tonight, try these giant sets:
set 1, 4 rounds:
squat, 10, 8, 6, 4
hack squat 12 reps
leg curls 12 reps
standing calves, 12 reps
when done, do 4 set of squats for a single each (optional)
set 2, 3 rounds:
leg press, 12 reps
leg extensions, 12 reps
seated calves, 12 reps