INTRODUCTION:
In this tutorial, we follow the same steps and techniques as my other ‘lips’ tutorials. I figured it may be helpful for some to see how the same techniques can be applied in quite different paintings. 

Don’t get discouraged in the initial stages when it looks rough, it only matters what it looks like when you’ve finished :)

There is no ‘right’ or ‘wrong’ way to go about it. Have a look at other artists techniques and adopt one or adapt to suit yourself, it all comes with practice.

I mostly use a single brush in Photoshop, just the soft round brush, but vary the size and pressure using a Wacom tablet.
Start off with basic sketch layer (an additional layer we’ve added above the background). Then, because I sketched on a dark background, I inverted the colour and changed the layer blending mode to ‘Screen’ (I could have just sketched in white on a dark background). Create a new layer as your painting layer under the sketch layer.
I then paint the skin around the lips to a reasonable level.
I keep working on the surrounding face which is easier than if the lips were finished. This means I can use a larger brush for softer, more blended colours and not worry about overspill.
I keep in mind that the lips don’t have a harsh line around them, they need to blend into the surrounding skin (unless you want strong lipstick edging), so I try and keep a soft edge.
Base is down and I’m reasonably happy with the lighting. You can turn the sketch layer on and off as needed for guidance.
Once I have the base down, start lightly adding the wrinkles and folds. Remember where the light is coming from and resulting shadows and bounced light.  I created another layer for the highlights. Looks rough at this stage but don’t worry ;) These lips have several levels of highlights. You may end up with several layers of highlights, with varying opacity, blur or effects.
Remember, just as if you were on a large canvas, if you view anything from farther away, you don’t see imperfections. So, you can zoom up and be quite rough, then zoom out and see how it looks.
Looking pretty good after about an hour or two ;)
The finished lips with surrounding skin, shading, highlights etc.
The Finished Painting