To create the optional salt rim: place about ½ teaspoon of salt into a shallow dish. Run a lime wedge around the rim of your glass and press gently into the salt. Shake off any excess.
Place lime juice, orange juice, grapefruit juice (optional), non-alcoholic tequila (optional) and agave into a shaker with 3-4 cubes of ice. Shake for 15-20 seconds then strain into your glass over fresh ice. Leave as is, or for a sparkling version, top with your lime sparkling water. Garnish with fresh lime and serve.
