I really don't see shape well, some people are lucky and see shape, I see motion.

I use a combination of my naked eye, the stuff I pick out of the corner of my eye/instinct and then use the binoculars to look closely. A lot of false alarms.

Ear twitches are the biggest giveaway for me.

Different at low light or in the dark. I scan lighter areas to pick out the darker game animals or the contrast.

One thing to remember, don't get twitchy, slow and smooth, they pick out motion well also.