Perhaps my favourite discipline is working from the model.
This is where I probably experiment most with mark making and colour. I much prefer the quick poses of course as with most of my work the less time I have the better! I try not to look at the paper/board when drawing finding that the lines I produce are more faithful to the figure that way.
I often ask the model to create a series of movements which I then translate onto the paper changing colours from one position to the next.