You should try working from a subject, rather than just free-forming ideas.
(with people in specific)
When you work from a subject, try to concentrate on a piece of the picture rather than something whole. As in... don't think "hand" think "finger, fingernail, this knuckle, that knuckle, the rest of the knuckles, bend in skin..." The problem most people have with drawing is that they don't consider human form... as in, they draw two straight lines and call it an arm... whereas a real arm has so much definition and shading from muscle that it's hard to make a perfect replica of it.
If you REALLY want something activities to do, go out and find pictures of people, preferably in different poses and just trace them as best you can. When you get curves of the body down, try doing some shading. It's easy to get the idea of shading, but it's difficult to make it convincing in many situations.
Most importantly... DON'T RUSH. You'll get better to the point where you won't have to rush sooner or later, but for now, take your time and don't be afraid to work slowly and give detail to the picture.