Pour 2 cups cold water into a small pan; add 2 tbsp culinary-grade lavender.  Bring to a boil.  Remove from heat immediately.  Allow to cool completely and strain.  Add lavender liquid to 4 cups of lemonade (of your chosing).  Sweeten to taste.  If desired garnish with lavender flowers.

Source for lavender: pelindabalavender.com