Cut a lime and rub edges of glasses with it. Then dip the glasses in a plate that has either sugar or salt or a combination.
Combine tequila, passion fruit pulp, triple sec and agave syrup in cocktail shaker with ice. Shake for 20 seconds. Strain in a margarita glass and garnish with a sliced lime.
Notes
Use silver tequila when making the margarita. Gold tequila can muddy the flavor.
While I prefer the pulp which you can thaw out, passion fruit nectar or juice can be uses as well. You can also freshly squeeze some or make your own puree.
Use agave syrup instead of simple syrup. It takes takes less work and adds additional flavor.
Crushed ice which will make the margarita colder quicker.