1 HOLD THE PEAK CONTRACTION.
This is accomplished in a couple different ways. The first and simplest is to hold the weight in the top, contracted position for two seconds on every rep. This increases the time under tension.
The second is to add bands to whatever you're using to hoist weight – barbell, trap bar, or Dead-Squat® Bar. The bands are particularly good because it causes you to fight for the peak contraction vs. just holding it. You're continuously working against gravity and a band.
Lower the weight with a controlled tempo and immediately reverse direction at the bottom without resting.