Hey there really nice drawings! I can see that you are tying to capture the line of action already! I think what your missing is to be more loose and focus more on the 'movement' of the pose first! You can do this by doing quick gesture drawing which is really effective for beginners since it helps to practice a lot of poses in a short amount of time!  I think you can try it by capturing the essence of a pose  Love life drawing as great videos about gesture you should check it out this is lone of the vids that i think will help you https://youtu.be/5bw3BW4Q6VM Proko's and mike mattesi video about gesture will also help you understand more about gesture https://youtu.be/IyuCq6VWVeA Hope this helps!