Don’t use a top-quality champagne for this – mimosas are a fantastic option when you open a bottle of sparkling that’s not quite to your taste.
I find the best ratio of sparkling wine to orange juice is 2/3 sparkling and 1/3 orange juice.
I haven’t included specific measurements as the size of champagne flutes can vary. Just eyeball your measurements, and then taste – adjust the sparkling and orange juice ratios to your own taste!