There's a few other things I've started doing, some maybe just luck/coincidence, take all with a grain of salt:

- In a stand bowhunting I MUCH prefer to shoot standing, so I slowly stand as soon as I can, even with the deer way out there.
- Move while they are moving, my theory is when they are moving it's harder to pick up other movement.
- Like Bronco said, if they are looking at you FREEZE, the "head bob" think is them trying to figure you out, depth perception isn't a strength for them and the head movement helps.
- I try to not make eye contact, something about predator/prey relationship. I will usually divert my eyes to the side, or stare at the ground under them, but don't lock eyes. That seems to trigger a run off.
- I've also started not moving after they look away. I swear once they think you are there, they try to trick you, they will start to feed and snap their head up, start to look away and snap the head back, I swear they are trying to trick me. Once they see me, I don't move until they are either walking or I can't see the eyes at all.

They definitely know about eye contact. I never make eye contact anymore. Never look directly at them.

-Jake

I most always move in slow motion. Move when they are head down feeding. I also try to move with the breeze or when they are walking. I always figured they would have more trouble hearing me when they are making their own noise.
Basically, I change my whole rhythm and try to slow way down. I've been busted enough times jerking my head around, I've learned to overcome the urge. I missed a trophy buck doing that once, got excited, and turned my head quickly.
There is definitely some correlation between actively looking for game and passively (lazily) looking. They can sense your tension I think. I'd spent a couple of weeks sitting a spot with good Deer sign, never saw a thing until I fell asleep and woke up with 14 Deer thirty yards in front of me.
Basically IMO if you try to see everything in all directions you will see little or nothing.

every place is different, every situation is

a rutty buck on a does trail will rarely look up or be alarmed, an old nanny doe with two fawns will be alert almost always ... in Arkansas, deer look up all the time, rarely do they look up in Kansas

if its a calm day, move very slow but very windy days you can swat mosquitoes and not be seen

They look up anywhere they've been hunted from treestands.
I got into the woods late one afternoon; too late to put up a stand and get up into a tree. So I settled into a brushpile on the ground. Shortly after that I had 2 fawns come out of the swamp and start feeding around my brushpile. One was close enough that I could have poked it with an arrow. Suddenly they both got nervous and ran back to their mom who had just come out to join them. She walked past me at 20 yd. looking up, scanning the trees. She never saw me, but she was looking.