Give Your Cell Shading A Little More OOMPH (Patreon)

Start with some basic flats, I prefer to keep them all on one layer for simplicity sake - if thats not your thing then you will still be able to do this, just on a bigger scale. If youre happy with your flats tho, but a little afraid to lose your individuals then duplicate then and merge one version and then you still have that safety net if something goes wrong.

Alternately save before you start merging and save the new file before you edit.

I usually just choose the skin colour to do my shadows, choose your light direction and go as extra or minimal as you like.

Your shadow layer will be set to multiply and clipped to the layer of flats. It doesnt matter what colour your main shadow colour will be - this part is all about just laying them down where you want them.

You can see the skin colour looks awful on Kon's plaid shirt when it's multiplied - you can barely see it

Now we unclip that multiply layer, create a new layer and clip it to your multiply shadow layer.

Now we get creative. Here you can see the different colours that I have chosen and where I used them.

I use a brush with a lower opacity so that it can have a more blended edge and also gratuitous use of the blending/smudge tool.

You can be as playful or as safe as you want to be - with Tim's sleeve I chose the complimentary colour of his red shirt just to see how it would look.

You can play with warm and cool colours, have some fun with it - create gradients of colours. Its very easy to just decide - nope that doesn't work, get rid of it and start again.

Once you're happy with your colours you can now merge your colour layer down tot he shadow layer. Turn the layer clip back on to your new shadow layer and~

This is a bit wild looking but you can see that it has a lot more dimension and character than one flat colour.

If you want you can do exactly the same thing with highlights