A favorite trick of a couple of old-timers I've known was to drive out and park somewhere in the country, throw the keys as far as they could manage, and then uncork the bottle and get down to business.
One of them once revealed that his "secret little trick" was to throw the bottle cap in the same direction as the keys. Since the cap was a lot lighter than the keys it wouldn't go too far, and was usually bright enough colored to stand out from the surrounding grass. If he could find the cap when he recovered enough to go hunting, he knew he was headed the right direction to find the keys and go home.