Step 1: Gather all your ingredients. Having everything prepped and measured makes the blending process quick and easy.
Step 2: Place the frozen mixed berries, vodka (or rum), fresh lime juice, and simple syrup into your Ninja blender.
Step 3: Start blending on a low setting, gradually increasing to high. Use the pulse function as needed to break down the frozen fruit.
Step 4: Slowly add the cold water or sparkling water, a little at a time, until you reach your desired slushy consistency. You might need slightly more or less depending on how frozen your fruit is and how thick you prefer your slushie.
Step 5: Continue blending until the mixture is smooth and evenly incorporated, with no large ice chunks remaining. Scrape down the sides of the blender with a spatula if necessary.
Step 6: Taste and adjust. If it's too tart, add a little more simple syrup. If it's too sweet, a splash more lime juice will balance it out. If too thick, add a touch more water; if too thin, a few more frozen berries or a small handful of ice.
Step 7: Pour the finished berry bliss slushie into chilled glasses. Garnish with fresh mint leaves or extra berries for a pop of color and freshness. Serve immediately and enjoy the cool, boozy delight!