How can I improve the flavor of a cheap bottle of sparkling wine? 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.