Hello! I'm not a professional or anything either, but I'll just give some feedback!
I think your life drawings of hands are very nice. I also like your outlining technique. One critique I would give, would be for the abs, where the edges of them could be less definite, as in less of a shape and more blended. Like I said earlier, I'm not a professional, and this is just how I would draw it;
That's a page from my comic.I hope I was helpful!