Place champagne flutes or small glasses in the refrigerator or freezer for 10–15 minutes, if time allows. Ensure the orange juice, sparkling water, and soda are well chilled so the mockmosa stays fizzy and refreshing.

In a large measuring cup or small pitcher, combine the cold orange juice and freshly squeezed lemon juice. Stir to blend, then taste; it should be bright and citrusy but not overly sour. This is your mockmosa base.

If your orange juice is very tangy or you prefer a sweeter drink, stir in 1 tablespoon of simple syrup or agave. Taste and add up to another tablespoon if needed, keeping in mind the soda will also add sweetness.

Remove the chilled glasses from the fridge or freezer. Fill each glass about halfway with the orange–lemon mixture, leaving room at the top for the bubbly ingredients.

Slowly pour sparkling water into each glass until about three-quarters full, pouring down the side of the glass to preserve the bubbles. Finish each glass with a splash of ginger ale or lemon-lime soda to add sweetness and a soft mock-champagne vibe.

Garnish each glass with an orange slice on the rim or a thin orange round slipped into the drink. Add a small sprig of fresh mint if desired. Serve immediately while the mockmosas are cold and fizzy, over ice if you like.

For a larger batch, stir together 4 cups orange juice, 1/2 cup lemon juice, and 1/4–1/3 cup simple syrup in a pitcher and chill. Just before serving, add 4 cups sparkling water and 1 cup ginger ale or lemon-lime soda. Stir gently to avoid losing carbonation, then pour into garnished glasses.