So what kinda weights are ya using on those lifts? Ma best ever squat was a buck 85 for 6 reps 
My weights are pretty low right now too. I used to be stronger.
I start with 12-16 rep sets with about 160.
Then i'll sometimes put it up to about 200 and do as many as I can. Usually about 4-8 reps. But I don't do this too much, I prefer the high rep sets.
At the end I strip it down really low to like 100, and i'll just squat until I can't anymore, just do like 30-50 reps until my leg muscles feel like they're about to rip in half. I usually do 2 sets like this at the very end. That shit KILLS the legs a lot more than low rep for sure.