Step 1

Place the cubed watermelon in a blender. Blend just until it breaks down into a liquid, about 30 seconds. Strain through a fine mesh strainer and mix with the tequila and lime juice. Taste for sweetness and add simple syrup, if you like it sweeter.

Step 2

On a small plate, combine the salt, sugar and Tajin seasoning. Run the lime wedges around the rims of 4 cocktail glasses. Dip the rims into the spiced salt mixture.

Step 3

Fill the glasses with ice and the margarita mixture. Garnish with small wedges of watermelon and the lime wedges.