I think the best way to get good at drawing is to look at lots of different manga tutorials and develope your own style with what you know, a bit of reality and a bit of japanese manga styling. I've been drawing manga for years and I'm not too bad, but I've combined about 3 different styles from tutorials I've found and manga artists I admire. There's no such thing as a quick fix, and you just need to take your time to become perfect.