How I can improve my poses

I always had problems with poses and gesture. I don't think I'm particularly bad on anatomy, but my poses always look pretty stiff and without life. Also it's pretty difficult to me to make new poses from imagination. So I enter in this page to try to practice poses every day and try to be better at drawing poses and gesture, and I would want any critique and or advice to be better at it. I'm struggling with the clases. 

Here are the drawings I made yesterday in the 30 minutes class, they're divided by the amount of time I drawed every pose: 
https://drive.google.com/drive/folders/1MTILCRiX5JOu8MwHi7CkR636b1LjezEB