I know you wanted to give a sense of depth, yet you might want to rethink your proportions. The torso seems way to large compared to the size of the arms and his hands are flipped around, his left should be facing up while his right should be facing down, like squat said. Also don't call your self a newbie because we were all beginners at one point. Another thing, when you dither you make another shade, many people just use it to make a small transition from one lighter shade to the other yet if you really want to make your art look more realistic the screen try using it like an extra color.