Prior to filming the Matt Kroczaleski/Iron Asylum video, Matt and I discussed which exercises would be best to do (which would make the "coolest" video).
We decided on squats, stiff-leg deadlifts, standing calves, and some sort of adductor movement. I told him that the order should be calves first, then stiff-leg deadlifts (doing them in a fashion so as to not hit the lower back too hard), then adductors, then finish with the high rep squats.
Matt wanted to hit squats first though, when he was fresh, and said he would be fine for the other stuff afterward. Well anyone that watched the video can see that this wasn't the case - after the squats, he was pretty much done.
So if your routine calls for heavy, high rep squats, I highly suggest you put them at the END of the workout. This allows you to hit the other exercises hard, and also allows you to leave the gym after you squat (which is exactly what you'll feel like doing, if you're squatting high reps to failure with an appreciable weight).
The same would apply to heavy deadlifts.
I realize that most powerlifters hit the big movements first in their workouts, but they usually don't do them for high reps to failure, and they also don't typically put as much effort into their secondary exercises (their number one concern is having a big squat, bench, and deadlift - not having big hanging hamstrings, big adductors, etc.).
Read more about Shelby Starnes' training here.