Open a 50x50 blank canvas,make the zoom 800% and click ctrl+L for the layers dialogue.
Whip out your pencil tool ( click N) then choose circle (01). Then we are going to make the circle, The ratio is 5-1-2-2-1-5.
Step3(optional, if your circle isnt in the middle).
Select the select by color tool(shift+0) then click on the black pixels then do cut>open new layer>select none>paste>layer>merge down. All this does is center your circle.
Go to gradient tool and set your foreground to a light version of the color you want to use and for background choose the same color but darker. Im using yellow so my foreground is
#edf478 and my bg is #eaf62b. The go to gradient tool set shape to radial. Then select your fuzzy select tool (U) and click INSIDE your circlish thing . Then drag your gradient from left to right. Reminder: where you start the gradient is where the lighting is going to be.
Make 2 new layers. The first call it eyes and the second call it Mouth. Ok time to make the eyes whip out your pencil tool (n) then decide how your eyes are going to be. refer to the images below for different combos, you can still use your imagination
step6. Hands can be made also be made. Its 2px-2px-2px-2px then add the light color from your gradient and your done.