Watermelon Basil Cooler

With a bunch of watermelon about to go bad recently, I went looking for a watermelon basil recipe that might make a great summer cocktail to try over the 4th of July holiday. Perusing some online options I came across this NYT recipe and loved its simplicity and versatility. Actually going to assemble it, however, was a bit annoying since it doesn't actually give the right proportions for one glassful. Here's the ratio I used:

4 oz. Watermelon purée
1.5 oz. Basil infused simple syrup
1.5 - 2 oz. Gin
Fresh basil or mint to garnish

Mix in shaker and strain into an old-fashioned glass over ice.

All good and well, but that's even a bit too cloyingly sweet for my tastes, so I tested out some modifications:

• Juice of 1/2 lime - this alone was very helpful to the recipe
• Substitute tequila for gin - not bad except didn't tone down the sweet factor much
• You could use white rum, but I wouldn't recommend it if you're looking to take away sweetness. If using rum, definitely add the lime - probably makes this more of a watermelon daiquiri, but whatever. 
• Substitute mint for basil in the syrup - very refreshing 
• Add a slice of fresh peeled ginger - a bit of unexpected zip but can be strong 
• Random discovery: Pour 2 oz. watermelon purée into 4 oz. of sparkling rosé wine - definitely not the cocktail I originally intended, but pretty damn good
• Best option: pour into a highball glass over ice and fill up with watermelon seltzer water, roughly 2-4 oz. to taste (I used a new-to-me option from Whole Foods called Waterloo) - this took care of the saccharine issue and added a little fizz - perfect for summer patio sitting. Could also be used with lime LaCroix or other brand soda water.

Simple enough to make but generally not a cocktail you make without planning to, with the basic prep work for the ingredients. With the proportions increased, however, I see no reason why this couldn't be made in a pitcher - virgin or alcoholic - but leave a spoon in the pitcher for stirring as the purée does separate if left sitting for too long.