This would go into art discussion, since you're discussing art, for future reference. Also, it takes many, many years of practice. I know you've probably heard that multiple times before, but it's true. There tons of things to study in art-- color [schemes], shading, style, anatomy, concepts, positioning, composition, connection, etc. You don't have to be great at all of them to be a good artist, though. Trust me, it's hard, just keep working. It doesn't happen overnight.