Sui Kune
Here's some (pretty bad) stuff I can do.
sweatdrop I haven't been able to draw anything for a while. The most I've been having trouble with is the outlines, as in, the "blocks" you draw as a template for planning out the figure before you fill in the details.
ok that's a start, i have no idea how long you'vebeen going at it so without more info from/on you my usable advice will be limited.
1: the fact that you are critical means you are aware that your abilities need improving, this is good, it will give you drive so long as you don't allow it to overwhelm you with depression. an artist is always their own worst critic (important) so they always have an inflated bias opinion wether it be positive or negative of their own work. this is a universal truth, no artist is immune to this. maintain a balanced and objective view of your own work, but don't rely on the opinions of others until you're not sure of your progress, you know you need to improve and you really don't need other people blowing smoke in your face about your abilities.
2: improving your skills and developing your own style takes TIME and lots of it, i've been doin this for 8 years and i'm still gettin there. it is an infinite process, you never ever ever learn and master everything in art, so you gotta focus on what you like. don't be afraid to ask for help, there is no shame in it. and never ever get hung up on the ideals of art with people, especially your teachers. practice in whatever form you find it is always a good thing. developing your own style is a stage to save for MUCH later, first you must focus on understanding basic techniques of art/drawing/manga style, before you develop your own individual presence therein, and your style eveolves on it's own anyway, so don't get hung up on it
having gotten that out of the way, theres not much specific tips i can give you until i see more of what you're capable of (a persons overall abilities and knowledge cannot be gleaned from images alone, so i try to listen more than i speak when it comes to teaching art)