Small characters like Terriermon consist of two circles. So for the pose, draw two circles and connect them with a curve.

Make ovals for the arms and legs.

Make an oval where you want it's ear to start, and draw the ear very loosely. Terriermon has cool floppy ears. Draw other details such as the tail, horn, etc.

Erase your guidelines to create a clearer image and mark the spots that will be a different color.

Coloring!

Create a new layer and outline. Use an art pen, marker, pastel...anything to outline your picture. For a bolder look I go over the border of the picture twice.

Return to the background layer. Color in the green areas and the mouth, then create a new layer and shade the image. Color the green areas in and the mouth red. Choose a spot for the light to come at and shade the opposite side a darker color. For white shadowing you don't have to always choose a light gray. Light blue, purple, yellow and almost every other color can be used to get a better shading effect.

To check if you're shading is good you can make the bottom and top layer unvisible so all you can see is the shading. If you can see the pose of your character with only the shading then you most liekly did a good job.

Switch to the bottom layer. If you want to, you can shade with a lighter and darker blue.