I actually did this not for sharing, but it might be helpful... and a good repitition for myself.
2.: diffuse. if you do it in color, you can use quite strong saturation here, because when you add light and shadow, the saturation will get back, unless you spend the time mixing the in-between colors.
3.: going in with hard brushes and high opacity but with penpressure. always picking the midtones and paint them over the unmeant edges.
5.: if you like softbrushes...: use them with lower opacity (i suggest 20-50%) to get some more refinement.
6.: darken the edges, where surface touches surface (ambient occlusion)
7.: highlights. here you can play around get some structure in.
8.: light reflection.
this technique can be used for several materials. you can play around by changing the rolloff of the shadow, the highlight...