This isn't a tutorial per say, but I did happen to have layers of the piece at various stages so I figured I'd explain what I did from one to the next.
1. Basic black and white painting of values and composition.
2. Started coloring and experimenting with lighting. I wanted the piece to imply heaven or divinity and this lighting style didn't really seem apppropriate for that so...
3. Altered the color scheme again. Closer, but I still wasn't happy with it.
4. Stripped the painting of the colors, and then tweaked the highlights/shadows. Refined the bulding for detail and clarity. Added some textures.
5. Final piece. Achieved intensity and qualities of lighting I was after for the most part.
Again, this image isn't really suppose to be educational or anything. Who knows, maybe I'll try a proper tutorial in the future.