I'm still searching my files for more storyboard frames, but no luck, I may be finished posting that kind of material. Here are a couple of illustrations from my book Art & Illustration Techniques.
This is an assignment from one of my New York clients. I sent the above sketch to my client for approval, the art directors often ask for a color sketch before I proceed with the finished art.
Here is the final acrylic illustration which includes all of the changes that the art director requested.
I'm not sure who this illustration was done for, probably was an assignment from Transcontinental Travel Bureau. This art was done using markers as well as acrylic paint.
My Art & Illustration Techniques book has many more examples, it was published in 1979, but used copies are still available through Amazon and used book dealers on the internet. The cover art was done using markers.