Tips: No grenadine? No problem. To make your own homemade grenadine, combine 1/4 cup pomegranate, cherry or cranberry juice (or water if you don't have juice) and 1/4 cup sugar in a small saucepan. Heat to steaming over medium-high heat, stirring occasionally; cook until the sugar is fully dissolved. Remove from heat and allow to cool. Store in an airtight container in the fridge for up to 2 weeks.
Use Luxardo maraschino cherries (like the kind in the photo), if you can find them, for a sophisticated look and flavor.