i have this huge habit where whenever im drinking out of an aluminum can, be it a beer, a soda etc... i notch a dent with my thumb in line with the mouth opening on the can. this allows you to grab the beer/soda/whatever and sip without having to look down at the can. its a great habit to pick up.
i also have a habit of whenever i open a glass beer bottle i have to rub the top of the bottle with a clean part of my arm. like twist it on my forearm as if there were something on it that needed ridding.