Here's a quick demo I did for my students in Denmark. A few of them wanted to see my process in designing a character from the idea to the finished stage. For the purposes of time I kept it pretty simple and really rough.
1. I start with doodles, rough shapes, quick sketches to get an idea of the silhouette. They gave me the idea of a boy with glasses holding something. This stage is where I have the most fun and usually do more than one rough but again the demo was quick.
2. Then I copy the rough, scale it up, turn the opacity down and do a cleaner sketch adding all the details. The glasses, the sweater he's wearing, a pipe (to fill with candy) and of course chuck taylors.
3. Once the drawing is done I fill in different elements (the pants, the sweater, his skin, his hair etc) and create clipping mask layers above those elements to add color, textures and shadows etc. These really help with painting gradients and keeping stuff separate in case you want to do variations or need to change something quickly. I keep going from here until it's finished and viola. Pretty simple and rough. You can go as detailed as you like but I like to keep my stuff less rendered... showcasing some of the quirky lines in my work. Any who, just wanted to share it with you all =]