A little something to demonstrate how I shade things. This has been "Made with deviantART muro
" so you can play back the progress and see it in action (Though you might want to slow it down so you can see it). It basically works like this:
1: Block in an area with the shading color you want. (Even in a new layer if you like)
2: Erase or paint over with a lighter color using a soft brush until you get the desired result. Adjust the brush size as necessary.
3: Repeat the above until you get the desired result
That's really it.
Pretty simple but effective and consistent.
This even works with texture brushes since you can use the same brush to erase/lighten and fill to give it the same consistency in texture throughout.