I want to use my lemon liqueur.

Great choice! Lemon liqueur is a versatile ingredient that can be used to create a range of delightful cocktails. Given your interest in using lemon liqueur, the top cocktail I would recommend is the Limoncello Spritz. With a remarkable rating of 4.9/5, this cocktail blends the sweetness and tartness of lemon liqueur with the effervescent bubbles of champagne or prosecco and a dash of soda water. It’s a refreshing drink that's perfect for those who enjoy a bit of citrus zing in their cocktails, embodying the essence of an Italian summer in a glass. It's a fantastic choice for social gatherings or any occasion where you want to impress with a sophisticated yet refreshing beverage.

If you're in the mood for something with a bit more kick, you might enjoy the Lemon Drop Martini. Scoring 4.7/5, this classic cocktail combines lemon liqueur with the citrus punch of fresh lemon juice and lemon-flavored vodka, all balanced out by the aromatic sweet tones of Triple Sec. Served often in a sugar-rimmed glass, this martini is a bright and zingy treat—ideal as an appetizer for a lively evening or simply when you crave something sweet yet tangy.

For a longer sipper, consider trying the Limoncello Sparkle. With a score of 4.39/5, it's an exciting blend of lemon liqueur, Cointreau, and champagne that results in a sparkly, citrusy delight. It's an excellent choice for any occasion where a lighter, more refined drink would shine.

Each of these cocktails offers a unique way to enjoy your lemon liqueur, so whether you're in the mood for a spritz, a martini, or something sparkling, you'll find something delightful to sip on!