30 minute class - critique and feedback all welcome!

Hello line of Action'ers!

Have been using the site for just over a year now and figured I'd share some sketches to get some feedback. I work in the animation industry so started up sketching after a long layoff with the aim to improve weight distribution, movement and overall drawing abilities.

I've been watching some Stan Prokopenko videos lately too, so am trying to introduce the concept of rhythm into my work to make things seem a little more fluid/alive.

Any feedback and critique would be awesome!

https://imgur.com/a/7EleUCL

I've been taking drawing seriously for only about 10 months, so take my feedback with a grain of salt!

Overall really good! I'd say for the 30 second ones, make sure to always have a clear landmark on the head to establish its orientation, like the ears you have in some of them or a line for the front of the face. For the 1 minute ones, you do already do a decent job showing overlap of the different volumes, but I think you could get a bit more if you worked on it. Particularly, the top left one is a bit flat (I also have a harder time with sitting poses). Your 5's and 10 are honestly beyond my critique. They have a great sense of volume and shape. Maybe try adding a bit more anatomical detail like muscles?