Hello! Nice sketches, good job.
I will give critique and advice on the figure drawings. First off - be careful to study the image and really draw what you see, not what you know. Look for the main lines and shapes and start there. One of your sketches is of the same model I drew just the other day so I tried to make a sketch to break down how I worked with it!
When working on this piece, I started by drawing the head, and then the long red line that goes from her head to the tip of her heel as a long curved line. This is the main "line of action" in the image. By making this line first, you get more flow basing around it. Next, notice how most of her body fit into almost a box shape? Sketch that out! It helps a ton when trying to figure out where different limbs goes in relation to one another.
I see that you're using the circles on a stick figure method - which is helpful, but makes it easy to miss the real shape of the limbs. In this casem note how the arms and hands are built of triangles and rectangles. Don't worry about drawing sharp edges - you soften it up when you go over the image. Focus on drawing big shapes before details, pretty much! Such as the big cicle that makes up the chest.
You have a good start going for you, but I believe if you practice some more quick sketches to force your eye to stare at the big picture (ie, 30 sek and 1 minute ones, I know, it's hard, but it's worth it) to really soften up the pose, your wrist, and make it look more lifelike.
I hope this gave you some insight! It's a little bit hard to convey over text. :)
