James Gurney has a great blog, Gurney Journey with great resources for how he learns to paint imaginary characters with life-like weighting, color, and balance. He uses references photos extensively to help him figure out feel the emotions of the characters in his pictures.
“The idea is to get into the spirit of the action, feel the wind in your face and hear the screech of the pterosaur.
I think that’s more important than getting a photographically real piece of reference to copy. If you can identify with the weight and balance of things, and especially the emotion, you’ve got 90% of the problem solved.”