Create a background layer of 50% grey.
Create a foreground layer for Value Check:
Fill it in black.
Set the layer mode to Saturation.
Note: try to keep every section in each stage on its own layer. E.g. Skin colour layer, Skin lighting layer, Skin highlights layer, etc. This will help you make colour modifications at the end of the workflow (e.g. change hair to a different hue, make the skin lighter, etc.).
Clear up any lines (rough and scrappy edges).
If you haven’t done it on drawing stage, apply gaussian blur on lines.
Choose colours in the top left corner of the value range.
Use the Inker Flatter brush.
One layer per each part (skin, hair, etc) that shares the same colour
Use the Value Check to allow enough contrast between colours picked.
Remember the Rule of 3 for colour harmony (Primary 50% + Secondary 30% + Accent 20%)
After painting, check with a very saturated colour with hue contrast to check for missing painted bits
Paint everything except lips.
Select one of the layers and go to the Tonal Correction (or similar depending on the software).
Hue: to change the colour hue.
Levels: to change the contrast and luminosity.
Always check your modifications against the Value Check layer.
Take this opportunity to make any of the other layers' corrections.
“The brightest point of light”.
You can paint them on the same layer as the local colours.
Use Inka Flatter brush and
If it’s very reflective, choose full White. E.g. Eyes, lips.
If it’s not very reflective, choose the lightest colour of that surface and hue up a bit and move the value down to almost white. E.g. Nose.
In combination with reflective surfaces, you can choose the lightest colour, hue it up and choose an almost white value, and:
Paint a thick line using the Inka Flatter brush
Change to the eraser using the Soft Brush and delete the edges.
Light a bit the whole stroke by passing the eraser once or twice.
“Light going through object and enhancing a particular colour and giving some sort of a glow.” E.g. light going through your fingers make give a red-ish colour.
Helps making the character look more alive.
Create a new layer above the lighting layers and set it to Soft Light mode.
Select a very bright cherry red (#FF0000) and use the Soft Brush.
Paint very lightly on the areas that would be generally affected. E.g. cheeks.
You can also include additional colours such as makeup.
Create a layer above the flats and set it to multiply mode, and opacity to 20-25%
Select Inka Flatter brush in black.
All the shadows are done in this layer.
Select the Cell-shaded shadows layer
Go to Filter > Blur > Gaussian Blur and soften the edges by defining the radius value.
Don’t make it too blurry nor too sharp (e.g.~2.6)