In warmups pause your middle rep and let the bar sink you fully into deep position. So for example I do 6x60kg and 3x100kg - i'll pause reps 3 and 4 on the 60kg set and rep 2 on the 100kg rep. When you pause the middle rep(s) you'll find the subsequent reps to be of a fuller depth. I discovered this for myself again recently and it's worth sharing with others.
If you try it out, please leave feedback or videos. I might post mine too later.