Hi,
Hungry for more? Good.
Okay, you got a good amount of information here to get you started, but I have to say that you really need to grab tools, brushes, shaders, gradients, or whatever you can find and experiment with them. I know that some artists don't like to search for new tools or experiment with a lot of them, but it really is a part of the business at least to some extent.
A major part of developing art skill is much independent exploration and experimentation. After doing this for years now, I rarely need to ask a question because I go and grab tools and learn their strengths and weaknesses. You will with this strategy find ways to make characters that looks better to you than those examples eventually if you reach some level of artistic independence. For now it is good that you ask for help.
Some tips:
1) Work quickly in most areas of the art
2) Erase and redo parts however many times that you need
3) Be bold and aggressive most of the time with technique
4) Review history file of your work periodically to learn from your progress
5) Experiment rapidly on a test layer overlaying the art on a regular basis, including the use of new brushes
A) Characters should all be each unique as practical in the game or scene yet have a common theme connecting theme if possible
B) People expect the cartoon nature of this genre, so really work it with some caricature aspects, even in the color choice being a bit exaggerated.
C) Better to have simple but clear boundaries rather than complicated or fuzzy ones, because the human mind intuitively prefers a solid distinction dividing areas
D) Keep the character free from attention grabbing parts which are below quality of the other parts, a common challenge for up and coming artists
I really like gradient brushes, which have made shading the textures much easier for me. Remember that erasing, including varying the opacity/ transparency of the erasing, is an important technique toward the end result of your brushes.