Step 1

If using a grapefruit, juice 1 medium ruby-red grapefruit until you have 4 ounces and strain out the pulp.

Step 2

Pour the grapefruit juice and 2 ounces gin or vodka into a highball or old-fashioned glass. Stir to combine. Fill the glass with ice. Taste and stir in simple syrup 1/4 ounce at a time if desired. Garnish with a lime wheel or thin grapefruit slice.