I really like the CSI lines you’ve used in a lot of those poses. It’s not easy really getting the gestural curve of something that looks quite straight like a limb, but you’ve done pretty well I’d say. Just be alert to instances where a gesture line gets more complicated than an S curve, and consider in those cases how to simplify it. Another thing you could do more (and this is helped by the looseness of your sketches) is try to connect gestural lines in rhythms that cross one body part to another. I second jean marc in saying that proportions are secondary to gesture, so don’t worry too much at this stage about getting relative lengths and things just right.