By the way photographers borrowed that technique from army snipers , that were using their gun straps in same way.
I belong to the generation that still was drafted for the army in Belgium. Our first month training in the infantry was with a long range automatic rifle. Of course, as a sniper you had to master it at one shot. I always used this technique instinctively when "shooting" with a cam.
That is, take the first resistance of the trigger, aim again, then hold your breath and steadily but calmly pull the trigger.
Fix your arms, elbows, head wherever you can: a wall, the floor, a doorway, anything stable. The only difference with shooting a rifle and shooting a cam is that a cam doesn't produce a vigorous rebound, so you don't have to brace.
I chose the Nikon D200 over the newer D80 a year ago because of it being heavier. More weight adds inertia hence less vibration. I hold the cam firmly on 3 points on my face: right lower eyelid bone, upper cheek bone, right side of nose bone. Right hand on the trigger... err... release button. Left hand supports the lens far in front, left elbow against my lower ribs. If possible fix my head against a wall or doorway. Legs wide spread, no slippers or socks (studio) but boots with rubber soles.
Sorry if I offend anyone with the obvious, but some people might not know.
I have a monopod but a cheap one without swivel. So I can't do portrait orientation easily. Moreover, the point at the bottom slips away on a hard floor when I bend over. With action shots, the telescopic monopod takes some time to deploy too and you can miss the moment.
So this rope trick is superfast (no deployment and you can leave the screw in place) and usable in any orientation and tilt on a hard slippery floor. Imagine your model moves 5cm forward a split second before the shot. With this rope you can easily go back 5cm without refocusing since the cam can move 360 degrees. With a monopod, your cam will tilt upwards and you get a lot of free copyspace on top ;-)
Credits for this link go to Duncan on the CanStockPhoto forum. I just dumped it here ;-)