DESCRIPTION
Time-lapse attached below! The image has some of the references I used, but there's more in the video.
I've painted pouty lips so many times, but I still usually need to take a picture to get it just right. ;-P
The software I use for the 3D model is the Magic Poser app, which I HIGHLY recommend. Super easy to use.
In the video you see a piece of pin-up art by Bill Randall, who's one of my favorites. I love his colors and playfulness so I like to have one of his pin-ups in my file to make sure I keep that vibe in my own work.