First off, lets get some basics down. Learn your anatomy. Medical diagrams are a good place to start. Highlighted are the main muscle groups shown when drawing. Certain groups will show more than others depending on how your character is built.
Shown here are 3 of the body types you can get. Skinny, medium build, and body builder. Most artists tend to stick between skinny and medium. Its difficult to get a head to look right on a very large body, and its not typically 'pretty'. But don't be scared, experimenting is key!
Tip: See how the different muscles appear as the character gets bigger? Some bigger characters have more built arms, or abs. Once again, the medical diagrams will help you understand.
Jawlines are essential to the feel of the character. In figure a, the chin comes out a bit, and the jaw is wider and much more square. This is typical for a male with a high amount of testosterone.
Figure b shows an effeminate male, with very smooth curves. His cheek is slightly less chiseled and his chin is round.
Figure c is a boyish or young male. His chin is pointed and his jaw angles upwards more than the others. His face is also wider in general.
Note: Also, look at the noses. Mix and match. You may end up with some fun results.
Eyes are important. They tell alot about the characters personality. Here are some examples.
a) fairly wide and open, but on edge. It doesn't feel as though its that wide naturally, so usually used for a scared character.
b) Quite laid back. It is neither wide or narrow. Used for characters who are very neutral.
c) The feminine adaption of a. Comes across as less wild, and much softer in character.
d) For very observant or sadistic personalities. The small pupil usually gives a feeling of being 'switched on'
e)Naturally wide, no force in it. Used most commonly for trusting, kind types. Also works well with minimum eyelashes.
f) The angled eyes are commonly used for sly, scheming characters. Small pupils once again show that they're observant.
Now lets start on that picture. Rough out the skeletal base. Nothing fancy. The blue line shows his motion. Its good to get the angle of motion and center of gravity right before going any further.
The basic shapes for the torso are a little bit complicated. The ball at his stomach is where everything pivots. The top half mimics ribs, and has 2 squares for the pectorals. The bottom is just the pelvis. Usually a triangle would suffice.
Add in the arms and legs. Cylinders work well for this part. The feet are a bit more difficult. The best thing to do is look at a picture of feet and work out the shapes that you see. Use squares and circles for the hands.
Tip time: Notice how the left hand is smaller because of perspective. The closer to the viewer, the bigger.
Add in the basics for the head. Map out where you want the eyes. Use a triangle or Diamond to place the nose.
This step is optional. I like to flesh out the torso, even if clothes will be covering it. Notice how the right side is stretched and the left is scrunched due to his pose. Also take note of what muscles appear. His abs aren't visible because hes bent over, so any excess fat would cover them. If he was the 'body builder' type, they would still be visible.
Start on the smaller points. The face, hands and feet are a good place to begin. Look up some shoe styles and try copying from them.
Tip time: Notice how the left foot is less detailed? Thats because the further away an object is from the viewer, the less detailed it needs to be. This usually only applies in long distances like scenery, but it can give a picture some real dynamic. Use this technique sparingly.
Add hair and anything around the head area. In this case, the scarf. Due to his motion, the scarf would fly back.
Draw out the basics of the top. Personally, I don't add creases or folds yet. Look in some magazines to find a style that suits the character.
Add in pants. Because they're fairly tight, they follow the original guides closely. With this type of material, knowing about leg build is useful when shading comes around because it would cling to the shape of his legs. Add some basic folds. Because they're tucked into the shoes, the bottoms are scrunched up.
Tip time: Add the seams of the clothing. There are few materials or items of clothing that don't have seams.
Nearly done! Add the main theme of your picture. In the case of this particular one, feathers. If doing this digitally, put these on an new layer as you may have to erase some overlaps. I also added belts for fashion purposes. If you didn't do it before, add the creases in.
Tip time: There are more creases on the left side of his abdomen. This is because hes bent over. Material moves with the body, so the right side is smoothed out.
Finally finish off with any extras. The flying feathers and fire all move in the direction of the scarf. This gives more movement. Also, erase any overlaps, like the hair under the feathers.
Complete. Well done! Keep practicing!