Toon shading on particles

Hey there. I’ve been struggling with this issue on my own for a few weeks now and simply CANNOT figure out how to achieve the style I’m going for. Here are the two looks I have been able to achieve so far (please be kind, this is my first attempt at anything 3d!). All I seem to be able to get is either a smooth, toon-like rendering of her hair with NO shading, or the shading works, but picks up all of the little details and particle intersections that I would like to pretend are not there:

And here is a Photoshop image of what I want the rendering to look like (smooth, bold contouring AND shadow).

Any ideas would be greatly, greatly appreciated. Thanks