Extrapolation - seeing beyond the pose, "Nobody is going to know if you changed the pose, just make it interesting;"use the model as your jumping off point, don't be married to it. In the photo below the top drawing is of the model's actual pose, the bottom is how Matt interpreted it.
Exaggeration - push the pose farther than what you see in front of you to give it more life; when viewing a live model your eyes take in so much more information than when viewing a drawing so you have to exaggerate the drawn pose to compensate
Alright I cheated a bit this week. The poses were supposed to be 1 minutes which I respected BUT I spent some additional time cleaning up the poses and fixing proportions. Without a very good understanding of anatomy and proportions, it is really really hard to draw a pose in less than a minute, especially when you have to turn the model around so the silhouette reads clearer. It must be possible with experience but I am not quite there yet. Give me few more weeks ;-) - Oliver Ladeuix