Not necessarily stirred as much as swirled - you don't want to bruise the alcohol of choice but still need to allow for a bit of friction. One key thing a lot of people seem to forget is to use frozen (as in, stored in a freezer, not the state of matter as it wouldn't freeze anyway as we all know :-) gin or vodka. As it's meant to be enjoyed over a longer period of time than a typical cocktail, you want your liquor of choice to stay as cold as possible for the length of time it takes you to drink it!