Toast the coconut. Remove it from the heat and place it in a single layer on a plate.
Add a bit of extra cream of coconut to a separate plate and dip the edge of the rim of the glass into it. Then dip the rim into the plate of toasted coconut.
Place the tequila, triple sec, lime juice, and cream of coconut in a cocktail shaker and add one handful ice. Shake until cold. Strain the margarita into the glass with the coconut rim. Fill the glass with ice and serve.
For a pitcher: add 2 cups tequila, 1/2 cup triple sec, 1/2 cup lime juice, and 1 cup cream of coconut to a pitcher. Add 3 handfuls ice and stir.