Here is a sample of my method.
Usually, I like to start my illustrations with a lot of sketches. I prefer to use down-maket paper during this step. The cheaper the better, because I noticed that I'm completely inhibited everytime I sketch on a sheet of good quality paper... it feels like a waste of resources. I need not to worry about the medium that I use in order to fully concentrate my attention on my drawings.
Then, when I'm happy with my sketches, I start the inking part. I use my computer for this, but I miss the sensations of a chinese brush and a crowquill when I go digital...
Paradoxically, it's a very relaxing time for me. I can ruin hours of work with just a few bad lines, and yet, it makes my stress vanish.
Finally, I add the shadows and the highlights. That's what gives a form its "taste", and its volume.