Pixel Avatar Step-by-step

1. Shade using a pen tool

2. Use pencil tool under 1px thickness and outline it. Clean up the lines with eraser tool under "anti-aliasing" and 1px.

3. Pick a palette that works well with each other.

4. Flat color. Use fill tool.

5. Shade everything. I magic wand the specific region and shade it using Burn/Dodge because I'm lazy.

6. Make line color match the regions.

7. Fix up anything that looks bad, such as bad colours.

8. Optional: Add a 1px white stroke around the object.

Final result: