Start by gathering all your ingredients and equipment.

If you are making your own simple syrup, combine equal parts sugar and water in a small pot, bring to a gentle boil, stir until the sugar dissolves, then let it cool.

Using a jigger, measure out 3 ounces of vodka.

Measure and pour 1 ounce of fresh lemon juice into your shaker.

Add 1 ounce of simple syrup to the shaker.

Fill the shaker with ice cubes to chill the mixture thoroughly.

Seal the shaker tightly and shake vigorously for about 15 seconds.

Strain the mixture into a chilled cocktail glass, garnish with a lemon slice, and enjoy immediately.