Here's a little process for anyone who is curious about the methods to my madness.
1. First thing I do when I open up Photoshop is create a new layer. Then, I do a rough sketch with the default brush at 7pts.
2. After the rough sketch is done I drop that layer's opacity to 20% so I can then use it as a guide to trace over top of.
3. I create a new layer on top of the rough sketch layer and with the 7pt brush size I draw the black outline. This process is very similar to inking in traditional comics. When doing this I make sure that all of my lines are connecting so that there are no gaps anywhere for the next step.
4. I use the paint bucket tool to fill in the flat colors. If there are gaps, then the WHOLE canvas will fill in with the selected color instead of just the part that I want to color. In the case of the image below, I just want to color the face.
5. The paint bucket doesn't get everything, so I go in with the brush to fill in those areas like the little white spaces below.
6. Flat colors are done. Now for the shadows.
7. When flat colors are done, I then use the lasso tool to make a selection of where I want the shadows to go. Then, I paint bucket fill with a darker version of the base color.
8. To add a little color in the 'RED ZONE' of the face, I grab a bright red with the brush, then drop the brush's opacity to 5% and color on the ears, cheeks, and nose.
9. Almost done. Just adding some finishing touches. Add the highlights to the hair, nose, cheeks and a blue rimlight in the shadow area. And, wha-la! Done.
There will be more process to come. This is just how I do the foreground characters and elements. The background is pretty close to the same process with a couple more added steps here and there.
So there it is. Enjoy.