Fill three highball glasses with ice.
Add 1 shot of tequila to each glass.
Add 1 ounce (3/4 shot) cointreau to each glass.
Top each glass with grapefruit juice.
Garnish with lime and grapefruit slices.
For the Salted Lime Rimmed Glass
Place 2 TBS of fine salt on a small plate or in a dish.
Zest a whole lime on to the salt.
Use a fork to muddle together the salt and zest so the lime zest oil infuses the salt.
Rub a slice of lime around the top rim of the glass.
Dip the glass into the salt. You might have to roll it around to ensure you are getting all sides of the glass.