Add the apple juice, banana slices, frozen berries, and Greek yogurt into a blender. Blend the ingredients on high speed until the mixture reaches a smooth, creamy consistency.
If the texture is thicker than desired, pour in an additional ¼ cup of liquid and blend briefly to incorporate.
Taste the smoothie and, if preferred, drizzle in a tablespoon of honey to enhance sweetness. Pour into two serving glasses and garnish with a few fresh berries and sprigs of mint for a refreshing finish. Serve immediately.