Draw the basic shape of his head, ear, shoulders, and shield. The first stop is usually the most important because it gives the overall appearance of your drawing. If the first step is distorted, your drawing will be distorted.
Draw in the shape of his hair. Draw where his eyes, nose, mouth and ear will be, as well as some details on his costume. Pay close attention to how facial features look from the side. Use some of the many eye tutorials on this site to help with the profile view of his face.
Start shading in his head and map out the dark and light areas of his hair. Hair should be approached just like anything else, starting with the shape and adding shadows and highlights to give form. I used a technique called squirkling for his skin, which is basically just drawing a bunch of tiny circles really fast instead of just normal shading. It gives his skin more texture.
I started shading in his costume here. Crosshatching is a good way to give the costume a fabric look while still making it look tough.
This is just a continuation of the last step. Pay attention to tiny details.
Shade his shield to look metallic with curved lines going around the shield, then blur them with a tissue or your finger or whatever you like to use to blur things. Give it final touches, make sure you have good shadows and highlights. Sign it and you're done.