I love finding "smaller" artists and unique artists that just happen to have colouring books and Travis J Hanson is one of those that is a comic artist that just happens to have sold his line art as a colouring book. My only issue is that he's made it double sided and therefore I scanned in the image and printed it on Copic paper so I could give the image its due and not take 900 years to do it in just pencil.
I also used one of the sections of the Sandy Allnock underwater class for this, to do the bubbles. I pretty much knew the ins and outs of it (apparently that's a skill I have to look at something, pick it apart, and mimic it), but she had a sale on her classes during black friday and I picked up the mini classes. I'm really, really not great with classes because of the handholding and I do learn in such a "see it, do it" kind of way, but if you do need any help at all with your copic colouring they a great classes to check out. So yeah, I watched the bubble class for the specific designs on those and I'm mostly happy with how it helped me like the whale because I did like 3 underpaints on him and he just kept fading into the water.