Pour the Himalayan salt onto a shallow dish. Wipe the rim of each glass with a wedge of lime and place the wet edge into the salt to line the rim. For best results, rotate and firmly press the rim into the salt several times.
Fill each glass with ice. Divide the grapefruit juice, tequila, and lime juice between the two glasses and give the mixture a quick stir to combine.
To serve, top off each glass with some club soda and garnish with a lime wheel and/or a piece of grapefruit rind. Enjoy!