How can I improve on a cheap bottle of bubbly wine? I thought of a few ideas myself but instead of wasting it I thought I'd ask. BTW, by improving I mean make it taste better.
Make a kir royale with it.
Add a small amount of a strong, fruity liqueur to the bottom of the glass, such as creme de cassis or framboise (Chambord is one brand name). Then gently add the sparkling wine.
Often, cheap sparkling wine is not very palatable because it is bitter: the strong fruit flavors of the liqueur will mask this.
Why, a Buck's Fiz, of course! Two parts chilled Champagne (recommend a NV from a non-Grandes Marques Champagne house) or bubbly (chilled white sparkling wine that isn't from the Champagne region) to one part freshly squeezed orange juice from oranges stored in a fridge. This is a British idea, one that is traditionally served mid-morning or even as a chaser to a good cooked breakfast with top-notch ingredients! A Christmas morning indulgence or as a libation to kick off the day on any other celebratory occasion. What's not to enjoy about that, then? (Wikipedia)
I agree that making kyr royale is a good solution. Also putting some fresh and perfumed herbs in it will help. Try Lemon Balm or others that you like. Put the wine in a carafe together with some bundles of leaves, leave it in the fridge for 30 min.