Quarter the strawberries and cut up your peaches. I leave the skin on, but feel free to peel them if the skin offends you.
Place the fruit in a medium pitcher. Add the sugar and orange liqueur and gently mix. Refrigerate for at least 45 minutes (and up to 24 hours) to allow the fruit to macerate.
When ready to serve your sangria, add the champagne/prosecco and serve on ice. Celebrate.