Can I make this without triple sec?
Yes. You can swap in fresh orange juice (about 1 ounce per drink) or use a little extra agave. The drink will be slightly less citrusy and a bit lighter.
What tequila is best for a watermelon margarita?
I like a blanco tequila for clean, bright flavor. Reposado is also great if you want a slightly warmer, vanilla-oak note.
How do I make it less sweet?
Skip the agave at first. Watermelon sweetness varies a lot. Blend, taste, then add agave only if it needs it. A slightly heavier hand with lime also helps.
How do I make it sweeter if my watermelon is bland?
Add 1 to 2 teaspoons agave per drink, and a tiny pinch of salt. Salt sounds weird in a cocktail until you try it. It makes the fruit taste more like itself.
On the rocks or frozen?
On the rocks tastes sharper and more classic. Frozen is smoother and more dessert-like. Same ingredients, different mood.
Can I make a non-alcoholic version?
Absolutely. For the closest margarita vibe, use a non-alcoholic tequila alternative plus a non-alcoholic orange liqueur if you have it. No NA spirits? Replace the tequila and orange liqueur with sparkling water, plus a strip of orange zest (or a splash of orange juice). Add the bubbles right before serving.