Here's a speedpaint process I do when painting digitally.

I do a rough sketch using a rough brush which i'll use later on the fill in everything. I plot out the muscles and bones sticking out as well for guidance.

Next I add the shadows and midtones. At this point i just work on my figure and give attention to background elements later on. I sculpt the marks i drew earlier on, on where the muscles and bones stickout.

Highlight. I wanted a darker skintone so I did very little highlighting.

Draw in the background objects.

Gradient Map. Use gradient maps to asign a color to each gray value. I tend to leave the lightest/darkest value as white/black, but you can get creative with this

Add specular lights. This is how you can tell it's my artwork... the crazy lights. Lighting is fun, at this point u can use the light to better define shapes and make new ones?

Add another light source, this is supposed to be the "reflected light" but i always end up lighting it too much, it becomes one of many main light sources~ yay! Use the gradient tool and blending options to add more color. Add sparkles because he is a Superstar!~