I meant to pass on this simple yet effective technique for preparing a pink gin that Clive was kind enough to share. It produces, I think, a more subtly flavored cocktail than the straightforward method of simply adding a few drops of bitters to a gin and stirring it around.
Take the glass you're going to drink from and pour in some mineral water; swirl it around to thoroughly wet the glass and throw it away. Next add a few healthy dashes of Angostura bitters to the glass and swirl those about, taking care to fully coat the inside of the glass. Dump out the extra bitters. Add gin.
The result is a nicely flavored drink, not overpowered by the bitters and with a very pleasing color as well.