Technique Primer: Tall Clean
If your cleans crash, you’re slow under the bar, or you have absolutely no idea what’s happening and just fall down hoping for the universe to intervene on your behalf, use the tall clean as a technique primer to work on an active, precise pull under and turnover.
Pull the elbows up and out as you lift the feet to accelerate down with the bar close.
Then squeeze back like a rowing motion before spinning the elbows around the bar and up into the rack position, reaching your chest up into the bar to avoid gaps and reinforce an upright squat posture.
The goal is to never allow any space between the bar and your body so that you bring the two together smoothly as you sit into the squat.
To answer your question: 2-5 sets of 3-5 reps at the empty bar to 30% of clean or so. Remember that this is not a strength exercise—you do not get better by increasing the weight. You get better by doing the exercise better, and this is also not a high-hang clean, so cool it with the loading and focus on your movement.