I thought I disliked gin until last summer. My favorite epithet was to describe it as "rubbing alcohol strained through a Christmas tree". Original, I know. Gin's popularity has been on the upswing the last few years, and as part of my plan to revisit things I hated in my youth, I figured I'd better retaste a few popular gin cocktails.
I started with the classic martini. After making and tasting several different recipes, I settled on Mark Ruhlman's Classic Martini, but I have a few notes. This may seem obvious, but the better the gin tastes, the better the martini will taste. Bombay Sapphire is at the low end of gin I'll drink in a martini. I'm particularly fond of Hendricks. If you have a favorite gin, give it a try. I suppose the same goes for vermouth, although I'm not convinced that there's a difference between good and bad vermouth.
The most important advice Mark gives is to stir the drink for 90 seconds, then pause, giving enough time for 30g - 40g of ice to melt and cut the gin. In practical terms, I find that that is about the length of time it takes me to make a lemon (or lime) twist. And if you don't know how to make a twist, it's easy! I learned from the Chow video below.