Per serving:
equal parts Aperol and Gin
3 parts prosecco
less than 1 part summer fruit (strawberries, blueberries, sliced peaches - raspberries and blackberries don't stay together well)
sugar to taste.
For the individual serving, the sweet vermouth feels unneeded. Perhaps a 1/2 part, or St. Germain
For a pitcher:
4 cups assorted fresh summer fruit (berries, sliced peaches)
2 to 4 tablespoons sugar (optional)
1 cup Aperol or Campari
1 cup sweet vermouth
1 cup gin
2 750-ml bottles chilled Prosecco