Makes about a quart, original recipe here:
<https://www.liquor.com/recipes/lemon-drop/>

16oz (2 cups) lemon vodka
4oz (1/2 cup) triple sec or Kelly’s orange brandy (unsweetened)
10oz (1 1/4 cup) fresh squeezed lemon juice
6oz (3/4 cup) Torani Sugar Free Simple Syrup

Optional:  fresh basil leaves to muddle 

Mix all and place in 1 qt+ container in the fridge (former tonic water bottle works great, as it holds just over a quart).  To serve, pour a small amount in a glass with a bit of crushed ice and muddle fresh basil leaves (2 large, or several small) until bruised, then top with crushed ice to about the halfway point of the glass and add the desired amount of the mixed drink, generally enough to just cover the ice.  Traditionally this is mixed in a shaker and poured into a sugar-rimmed glass, but obviously I’m skipping that part.  :-)