Zest two of the lemons to make about 1 tbsp lemon zest
In a small bowl add sea salt, sugar and lemon zest and mix. Place on a shallow plate. Wet the rim of each margarita glass and rim glasses by placing glass upside down into sugar/salt mixture.
Juice all 4 of the Meyer Lemons over a seive to ensure no seeds get into liquid.
In a large cocktail shaker add 1 cup of ice cubes, 4 oz Meyer Lemon Juice, 4 oz of Cointreau and 4 oz of Tequila. Cover and shake well with ice to cool. Gently pour into margarita glasses keeping ice out. Serve with a garnish of lemon and cilantro if desired.