Create a new layer and select areas that can be highlighted on her blouse and fill with a lighter blue than the one you chose. You can also select dark areas and make them darker. Then do the same for her hat.
If you
make all the layers visible by clicking where you made them invisible,
your image should look almost like this at this point:
You may have different shading but that's
alright.
Now make the layes invisible once again so you see the main photo, click on the skin layer, make it invisible (since clicking on it makes it visible), create a new layer and shade her skin the same way you shaded her blouse.
Click on the layer before the skin, which should be the "background" and fill it with a color of your choice. This will be the new background - make it invisible so you can fill in the details of the face.
Lips:
Create a new layer at the very top and make a base color then do the
shading similiar to how you shade the blouse and skin, while you are
at it - you can finish shading the hair. When you shade the hair,
just outline the earrings as well and fill in a light gray color.
By now you should almost be through. Just add in the eyes, and touch up on areas you want to make look realistic. You should have the style down pat by now.
Finally make all layers visible. The background may be showing between the layers but all you have to do is color it in with the brush tool or make tiny changes with the polygon lasso. Merge or flatten image and save.
Finally
Presenting: TWEET VECTORED!
You
can also take your time and use the eraser tool to curve the vectored
colored blotches... or Merge then posterize(Image - adjustments
- Posterize) or try different filters to see how it looks.
For example:
