In a blender, first add ice, then frozen lime juice concentrate, then tequila to help melt everything and finally the Controy & water.
Blend until smooth. If it is too frozen to pour, don't spoon it out. If it is that cold it will give you that nasty "Ice Cream Freeze" on your throat and soft pallet that will spoil the perfectness. Instead - add a little more water and blend some more. It won't hurt the flavor at all.
Cut Limes into triangles and use to wet the rim of the serving glasses. We do not use those big margarita glasses as they spill too easy and also spoil the perfectness. We use glass beer mugs. Dip the limed glass into the margarita salt to coat the rim, Pour the margarita, add a wedge of lime in the rim and be careful not to mess up the salt. Remember - it is the Perfect Margarita.