Some men get the 'tap' when she's done, almost like "uh ... excuse me, I don't know if you noticed, but the bus you're waiting for has left."
I recommend this site: http://www.beautifulagony.com/public/main.php This just shows the face/chest area in the various stages of arousal. I think it's really hot in it's own way. After watching freebies for a while you will see some universal signs. Peace Out, Rev J