With each of the movements I suggest to you, direct the movement with your own sub-vocal instruction. Flex and hold the tension in your knees. Knees release and relax. Continue to breathe gently and deeply. Contract the muscles in you thighs and hold that tension.
Thighs relax and release.
Tighten all the muscles and joints in your legs. Now contract the muscles of your buttocks. Contract your abdominal and pelvic muscles. Hold that tension. Instruct your muscles to release.