In a 16-oz mixing glass, gently muddle together:
 
1 large sprig spearmint
.75 oz simple syrup
Add:
Half a spent lime hull, and 1 oz of lime juice (no less, no more)
2 oz white rum
3 oz sparkling mineral water
 
Top with crushed ice and mix with a straw until drink is combined and glass is frosty. Resist the temptation to compromise with different rums, soda water, unripe limes, faux-mojito mixes and syrups. There's nothing like fresh, quality ingredients in a drink so perfectly simple.