Go through the basic tutorials on anime-style figure drawing, and try to keep to the order.

I've had a college-level life drawing class and I still draw placement lines for the limbs, spine and hips.

The two most important things: Practice, Practice, Practice and Reference, Reference, Reference.

I'm serious, try to draw at least 20 minutes every day, it's just like training any other muscle group.

Secondly, when you're just starting out, try finding a character in a pose similar to the one you want and don't copy the pose, just use it for guidance. Try printing it out, and drawing the main structure lines overtop of it. If you do this so that you can't see exactly every line in the original, it will help keep your drawing fresh but still use the same guidlines as the original reference.