is it cheap rotgut gin or decent gin? There's nothing you can do to make cheap gin taste good. In the case of cheap gin I suggest you save it to strip paint with.

If it's decent/good gin, try one of my favorites, the dirty martini:

3 parts gin to one part dry vermouth. Add a splash of bitters and a splash of the juice from the olive jar. shake with ice preferably. garnish with as many olives and cocktail onions as will fit on the toothpick.

tom collins is also good. Mix gin with club soda and sour mix.

Gin usually has citrus notes, so it mixes well with things that are citrus/tart. You can never go wrong with cranberry juice and gin.

Rollin down the street smokin' endo, sippin' on gin and juice....