Summer days are made for dining al fresco – and there's no better accompaniment to a barbecue, picnic or garden get-together than a sparkling tipple or two. From Instagrammable Aperol Spritzes to fancy Champagne Margaritas, these fabulous cocktail ideas are sure to go down a treat with guests. You don't need to buy expensive Champagne, either; Prosecco, Cava or any sparkling wine will do the job just fine. Get ready to shake up a storm!