i Do my squats like this.....

heavy days ill do 3 warms up sets. My last warm up set will be fairly heavy but ill only do 2 reps just so my CNS will be ready for whats about to occur. Then its 4 sets of 5-8 reps to failure..Rest 1.5 min and hit the next set...

on light days ill do 4 sets 10-20 reps 1 min rest...WOW what a pump i get from this..