Choose a coupe or rocks glass. Pour a small amount of lime juice on a shallow plate. On a second plate place the coarse salt or gold sanding sugar. Rub the rim of the glass once with the lime juice, then gently dip and rotate the rim into the salt or sanding sugar to coat evenly. Set glass aside to dry briefly.

Mixing

Combine ingredients

In a cocktail shaker add the reposado tequila, orange liqueur, fresh lime juice, fresh orange juice, agave syrup, and egg white if using.

Dry shake (if using egg white)

If you added egg white, seal the shaker and shake vigorously without ice for 10–15 seconds to emulsify and create foam.

Shake with ice

Add large ice cubes to the shaker, re-seal, and shake vigorously for 12–18 seconds until well chilled (the shaker should frost).

Double strain and serve

Double-strain the cocktail into the prepared coupe or rocks glass (over a large ice cube if using a rocks glass) to remove small ice shards and any residual egg white solids.

Optional gold float

For a gilded finishing touch, gently pour the gold liqueur or a small measure of very high-quality reposado (0.25 oz) over the back of a spoon held just above the drink so it floats as a thin sheen on the surface, resembling a 'Moneda De Oro' (gold coin).

Garnish

Garnish the rim with a lime wheel or orange twist. Float a thin lime or orange slice on top, or rest it on the rim to evoke the look of a gold coin. Serve immediately.