So it's been a while since I've had a model sit for me, but I got a chance recently with my Sis-in-law (Sister-in-law's sister?), Becca. If you've seen some of my recent work, you've seen her before - she's the blonde photographer in "Unusual Affinity" project.
Long story short, she made a visit to the studio and sat for a couple hours, in which time I got enough information down for me to finish the piece later. I think I could have designed the pose a little better, but I'm pretty happy with the color in the finished piece. I have north-facing window in the room, which provides what's called "north light." North light is a cool light that is reflected from the blue sky and remains fairly consistent throughout the day (whereas a western or eastern light would drastically change with the time of day and the position of the sun). Fortunately, the sky was overcast that morning, which helped to create an even more diffused light source, which helped create more neutral colors and softer shadows.