Looking for advice on choosing paint process

I recently started painting the Gale Force 9 Tyrannosaurus Zombie, but I was really unhappy with the colors I chose so I stripped the paint to start over. However, I feel a lot less confident in my ability to choose what paints to use.

I would love some advice and examples on how to paint exposed muscle, which I haven't found much of online. As well as general advice on how to paint a more realistic color scheme, as the Games Workshop/Citadel system does not give the results I want for this mini.