Bring 4 cups of water to a boil in a saucepan.

Once boiling, remove from heat and add the dried hibiscus flowers.

Cover the saucepan and let the hibiscus steep for 10-15 minutes, or longer for a stronger flavor. The water will turn a deep red color.

Strain the hibiscus flowers from the liquid using a fine-mesh sieve into a heatproof pitcher or jar. Discard the spent flowers.

While still warm, stir in honey or sugar to taste until dissolved. Start with 2 tablespoons and add more if desired.

Let the drink cool to room temperature, then refrigerate for at least 1 hour, or until thoroughly chilled.

Serve cold over ice, garnished with lemon slices and fresh mint leaves if desired.