My Level 3s begin with a 30 second “cast position” hold (a pushup with shoulders over wrists, shoulder blade round etc) than a 30 second hollow hold with arms up by ears than down by side, 15 hollow rocks, 15, Superman rocks, 10 pike compressions, a 15 second pike hold, (in a pike but all weight on hands, feet up etc) and 10 “ glide swing jumps” against the wall. This takes 5-7 minutes max and gets them to start activating the muscles needed for each skill. I keep this constant in terms of skills but change up number of seconds or time. I do a similar one for the 2’s and 4’s but slight changes to better suit those groups and the skills!