Here is a commission I did featuring breast expansion!

Another recent commission I did where the client asked for breast expansion and then a lactation edit. For this one I roughed out all 3 stages first to make sure the proportions were right. I draw on a gray canvas so when I'm copy/pasting it to show a client I erase with white. Its invisible when sent but on the original canvas it looks a bit silly.

After it's roughed out I reline it. This one the process was a bit different, so I painted the background first which included the giant fluffy tails and then I went into rendering.
Normally I use multiply layers for shading, but for this piece I simply locked each section of color and shaded/highlighted on the same layer. Then afterwards added a blue rim light. Once the base body and background were done, I simply painted over the base figure to do the alts.