Here is an example of our workflow for paintings based on your photos. Referencing your snapshots we do a speed painting on an ipad with a special stylus called the Nomad Brush. Preliminary work is done in monotone. We work out the lighting and composition at this stage. Virtual paint allows on the fly edits and saves wasting pricey paint and materials. Our "speed" painting is eventually transfered it to the painting surface creating an underpainting or sktech for the physical painting. Everything is still executed by hand one brush stroke at a time only we start with the Nomad Brush then finish with traditional brush and paint. We only reference the photo visually preferring the art to be entirely created by the hand of the artist. It took over a decade to develop our painting process in search of the best way to create stunning paintings from customer supplied photo reference at a price everyone would appreciate. It's a 21st century take on renaissance painting methods.
Here's a picture of the Nomad Brush for iPad. If you like to paint you should try one. It is not easy to master. Traditional paint and brush is easier to use by far, but the fact that we can do color and composition studies to full blown underpaintings without ever spending a dime on materials is a big secret to our success.
Here's a close up of the paint work on the canvas.