Hi! I like your last sketches they are full of character, However I agree with Enalya in the proportions corrections that she post earlier. Here's what I meant by studying Hampton, He has a book on anomy and I found it super helpful! I know that it may look very traditional or "academy-ish" but I think that learning the rules first so you can bend them later is the way to go.
Hope this makes sense, Happy Holy days!