Combine all ingredients except garnish in a cocktail shaker. Add some ice. Shake vigorously with the lid on and then pour directly into martini glasses. Add a strip of lemon peel to each glass to garnish and enjoy.
It is best to keep your limoncello in the freezer. Top quality limoncello will not freeze. Even when enjoying limoncello on its own as a digestif, it is best served straight from the freezer. The colder the better!