Add tequila, triple sec or orange liqueur, pineapple juice, lime juice, and hibiscus syrup to the shaker.

Fill a cocktail shaker with ice.

Shake vigorously until well-chilled and thoroughly mixed.

Strain the margarita mixture into a salt or sugar-rimmed margarita glass filled with ice.

Garnish with a slice of fresh pineapple or a hibiscus flower, if desired.