My suggestion would be to practice shooting while sitting down. You need more right arm strength(if right handed) to pull the bow back to help eliminate excess movement. I practice sitting in different positions. Taz suggested one. I like it when my left leg is straight and my right leg in bent with the right foot under the left knee. It allows me to better stability when shooting to the left. I also like both knees flexed slightly and my heels resting on the ground in front of me. I am able to hold my bow and rest my arms on my thighs, very comfortable. Left shot easy, straight shot very stable and right shot near impossible. You can shoot sitting down you just need to strenghten those muscles needed to do it.