This tonal approach is the basic and classic way to start a painting. It's a great way to guide your painting process because it includes an information about values (how dark or light things are) as well along with drawing of course. And it's more fun as well because you start with paint right away (in this case I used raw umber for underpainting).
Two major stages are shown down below. In reference picture there were two person behind the tiger and I found them quite disrupting in the composition so I had to edited a picture which effected a lightning of the scene. I hope that I somehow managed to keep the lightning believable....
tonal underpainting in the beginning stage (raw umber)
Final product called "Chill"