This is my process tutorial in Photoshop based on my master copy of Bouguereaus Dante et Virgile aux Enfers for the twelfth Open Figure Drawing Workshop (which incidentally if you are interested in joining are great fun and a wonderful learning experience). The finished image can be found here.
With this composition there are a lot of different materials covered here, from stone to cloth to skin - this tutorial will not focus on the individual properties of these per se (for one thing that would make a ridiculous amount of information in one humble tutorial), nor did I specifically focus on bringing out the different textures and properties of these on this particular piece.
What I hope to convey here is one of my techniques for digital painting, and my general workflow (without the extra processes one would need when creating an original piece, such as composition and colour theory etc). I hope that you find it helpful in some way, or at least an interesting read ;).
Throughout the entire tutorial I use one of Linda Bergkvists spackled brushes, and am ashamed to say I rarely deviate from this one and a small, round hard edged brush for detailing and line art. Use whatever brush you feel comfortable with (I plan to explore custom brushes much more thoroughly soon!) although my specific technique here involves gradually building up the colours through light strokes - therefore using a completely solid, opaque brush is not advisable. I almost always kept brush opacity at 100% - use your tablet to take care of the rest.
For those of you that have Lindas brushes, this is the one I adore and mentioned above: