Drag the picture into AI, set it to positive overlay, and lock the layer.

Tick the path with a pen and fill it with color. After the characters are hooked with the background color blocks, you can hide the draft (basically, you don't need the draft later, unless you want to adjust it, you can take it out for comparison)

Add a gradient effect to the desired color block, and then add a shadow along the edge of the color block. Gradient can produce different effects in many ways according to personal preference, try as much as possible.

Add highlights along the edge of the color block.

This is a crucial step, adding details, red cheeks, fabric patterns and lace of clothes. Flexible use of transparency, positive superposition, soft light, etc.

The effect of adding external light or shadow to a character. Here, in order to unify the style, the small trees and white clouds in the background also add a luminous effect superimposed on the front ~

Finally, you can add your favorite shading and borders. Complete-