We had a double model at yesterdays life drawing session. Within the same amount of time, 5 or 10 minute poses, as we normally draw one model, one becomes extra focused and concentrated. The models were very expressive. Great session!
I can't stress enough the importance of life drawing... It makes you understand shapes, anatomy, gestures, it is good for your drawing skills, it's a place to experiment freely, and also it's a lot of fun!