Steep the Herbs:
Combine basil, lemon balm, shiso, lemon zest, ginger, and green tea (if using) in a large teapot or heatproof bowl.
Pour in hot water. Cover and steep for 20–30 minutes.
Strain & Sweeten:
Strain out herbs and solids.
Stir in honey (or sweetener of choice), lemon juice, and optional floral water or vinegar/yuzu juice.
Adjust sweetness and acidity to your liking.
Chill:
Let cool to room temperature, then refrigerate until cold.
Serve:
Fill glasses with ice.
Pour over chilled herbal elixir.
Garnish with lemon or cucumber slices, fresh herb sprigs, and optional edible flowers.