Aaron Blaise, a skilled and well known artist visited Japan and he had open sketch day in a zoo. I went there and was able to walk behind him together with other participants, and was able to see how he capture animals on his sketch pad. His deep understanding and analysis make him enable draw perfect form of any creature regardless the subject being stay still or not during sketching.
While he drew animals, I tried capture him.
Thank you Aaron for the inspiration and those who organized the day as well.