Method one: Trace stuff. First off, tracing stuff is for children and animé freaks with no talent. Never do it once you learn how to draw what you want to. Anyway, find something you want to be able to draw and trace it. Once you're done, take a good look at what you've drawn. It's easier to draw something you've drawn before. Now hang your head in shame for tracing shit.

Method two: Study stuff. Learn the intricacies of your subject. To draw something, you'll want to be able to see it perfectly inside your head. If you don't remember a detail, you won't be able to draw it right.

Method three: Use guides. For complicated stuff, you're going to want to use line guides. I know, they're gay, but trust me--they help a lot. In fact, I used guides to draw Kilzek if he were human:

It's Human-like Kilzek!

Method four: Buy a book. Reading is great as it tells you what to look for when you're making your masterpiece. Books helped me out a lot when I first started drawing. For instance:

Before books.

After books.

Of course, you know you're a great artist when you're finally able to draw titties that aren't perfect spheres or grossly distorted. Be careful though, if you get too engrossed with drawing mammories you might end up making a lame comic that's nothing more than characters running around with H-cups spouting stupid jokes.

All great artists got their names in history by drawing great titties, so it might be a good idea to buy some books based solely around them. Studying boobies in public is great too, because an offended bitch's disgust instantly melts away when you tell her you're a starving artist and you're trying to get some "inspiration". Shit, she'll have sex with you right there nine times out of ten.