To make the fruit juice of your choice: In a sealable jar, combine the berries, herbs or aromatics and water. Muddle to release the fruit’s juices. Seal the jar and refrigerate overnight to allow the flavors to meld.
The next day, strain the juice through a sieve and discard the pulp.
To make the concentrate, combine the fruit juice, lime juice, simple syrup and vodka in a clean pint-size jar. Seal the jar and shake to combine. The concentrate can be used immediately or stored in the refrigerator for up to 1 week.
To make 1 cocktail, pour 2 ½ ounces of the concentrate into a Collins glass filled with ice. Top with 2 ounces seltzer water and stir to combine. Garnish with a lime wheel or an herb sprig, if using, and a few berries.
Repeat step 4 with the remaining cocktails and enjoy!