Thanks for the suggestion!
So here's my process.
To begin with, i do a rough lineart of the character/creature i'm about to study. Next, i use an opaque brush to block in the local colors on a layer underneath the lines. After i'm done i hide my referance, merge the color and lineart layers and start rendering, trying to define form (painting form shadows and cast shadows).
When i get to the point where i feel that the painting is finished (or im stuck) i reveal my referance and i make correction and adjestments by copying.
As for my actual technique, nothing special there. I use a regular round brush and one layer. As for the brush modes, i sometimes find myself using overlay and multiply (overlay brings out some sweet color varietion by saturating colors) but i still try to avoid them as much as possible. I want to learn and be able to paint everything by myself. Kinda as if i was painting traditionaly. I feel like modes and fancy tools are only there to help you paint faster, not better.
Anthony Jone's 'Painting like a sculptor and 'painting with confidence 1' have helped me a lot.
So yeah, i hope that helps. feel free to ask if you need more info