I did this mostly as a test of a new digital painting and sketching program I picked up recently called Clip Studio Paint. I needed some subject matter to sketch, so I chose to draw a dinosaur and get some studying in at the same time.
I started with a sketch of a T-Rex skeleton based on a photo. I decided that I'd go ahead and add the muscle and flesh layers on top of it. I've become more and more obsessed with finding information on dinosaur muscles since I've started sculpting them more frequently. I've found that it can be pretty hard to find good references for them. There are a couple really great drawings, that I use often, by Scott Hartman and Gregory S. Paul that helped a lot with this sketch.
Overall this was a pretty fun exercise, and I absolutely love Clip Studio Paint. I was able to jump in and get sketching pretty quickly. It's close enough to Photoshop, as far as menus and things go, that I didn't have to fumble around too much to get to the tools and options I wanted. The brushes perform beautifully and have such a natural feel. I especially like the colored pencil brush. I think its definitely replaced Photoshop as my favorite digital sketching tool. I have to experiment more with the painting side of things, but I've heard good things about it from friends and co-workers. I'm really excited to continue experimenting with the program.