Mix tequila, lemon juice, and Cointreau in a liquid measuring cup. For optional salted rims, rub 2 rocks glass rims with one of the lemon shells to moisten and dip in salt if desired; fill glasses with ice. Pour margarita mix into prepared glasses and serve.
Recipe by Three Many Cooks at https://threemanycooks.com/recipes/meyer-lemon-margarita/