Do three repetitions with 90 seconds of rest between each. And do them at the start of your workout before your arms wear out.
Get into a plank position with your feet against the wall and your arms directly below your shoulders, fingers spread. Raise your feet and press the soles of your shoes (or your bare feet) against the wall. Breathe normally, tighten your trunk and stand horizontally. Hold this position for 10 seconds.
From the horizontal position, bring your feet and hands towards the wall until your body is at a 45 degree angle. Engage your core again, tucking in your tailbone and squeezing your buttocks. Hold for 10 seconds.
Raise your feet (and hands back) even further, until your toes touch the wall and your shoulders cover your ears. This puts you in a handstand position. Hold again for 10 seconds.
Bring your legs and hands back to step 2 (hold for 10 seconds) and then back to step 1 (hold, again, for 10 seconds). It’s a full rehearsal. Give yourself 90 seconds of rest and then repeat.