This was a quick tutorial on how I go about making my sketches when I was on The Simpsons, or for any drawing. One thing I always tell people is to not worry about the end result, focus on the pose and the story you're trying to tell. Every pose has a story, weather simple or complex. The way a person stands can tell you a lot about that character, but this has more to do with character design than just drawing bodies. I added a pic so you can see my process.
1. When drawing a body I always start with a line of action, it's a guide that will help you flush out that perfect pose. Of course you also want to think about what emotion you want your character to have, and the line of action will express that. Oh and I almost never go with my first sketch, I always make several sketches until I find the right one.
2. From there I start roughly sketching out the torso, arms, legs, etc. Nothing detailed just yet, I want to get the right feeling for the pose before I start adding details. *notice how I pushed the 2nd pose to get more emotion.
3. When I'm happy with the way the body feels I'll add hands, feet etc. For me the hands and feet are an extension of the arms and legs, all flowing together. Remember bodies need to have fluidity. I also start to fix model problems like proportions and what not.
4. Still sketchy I start adding face details because I might want to change the body a little if I see the face. I also start to "commit" to my lines, meaning making them more refine rather than just quick strokes. This makes the drawing for solid, but notice how I'm still sketchy. Oh and always draw through your forms, example: Homer's sleeves and body, I draw the whole circle not just where I think it should go. *The lines on the floor is a little trick I use to help my characters feel grounded, or like they're actually standing on something. It's just a quick 2 point perspective and with it I can make any changes to make him feel like he's standing.*
Normally this would be the last part of my job because we don't clean up the drawings, but from here you can take some tracing paper and clean up the drawing. You can see in my clean up that I had to adjust his model because his body was looking a little to big. That's basically it in a nut shell. This is how I make any drawing, weather simpsons or not. Everyone works differently so just keep practicing and you'll find something that works for you.