1, file-new file.
2. Draw a draft:
3. Reduce the transparency and create a new layer. Hook line
Cross the line and delete the draft.
Color the new layer (pay attention to put the layer where the sketch is located on the top)
Apply background color (different colors are layered, according to the layer, the skin is at the bottom)
Shadows and highlights, (here you can use "Protect Opacity, Create a Mask or Selection")
In addition: the shadow on the marker is very soft, and the background color is paint bucket and pencil tool.
Finally: file-output to the specified format -JPG, you can save it as a picture!
Bonus: