The best way is with a hermetic champagne stopper.  This inexpensive contraption (Avanti Champagne Stopper, $7.95, Hill Street Home, West Hobart) will keep your left-over bubbly, well, bubbly.

This type of stopper uses the physics principle known as Pascal's Law: as pressure builds inside the bottle, the plastic nipple expands outward, creating a ‘bubble-tight’ seal, keeping the carbon dioxide in the liquid and your sparkling fizzy to the last drop.

Of course, refrigerate your sparkling promptly too: a colder temperature slows down the release of carbon dioxide from the liquid.

If you don’t have a hermetic stopper, you can use plastic wrap and a rubber band. Wrap the plastic wrap tightly over the mouth and neck of the bottle and secure tightly with the rubber band. This won’t create as good a seal as a hermetic stopper but it’s the next best thing.

The old “spoon in the bottle” tip you might have heard of, where a metal spoon is inserted handle-first into the open bottle, is, in our experience, ineffective.

Finally, there is no way you can force a cork back into a champagne bottle once it’s out. The only way to reseal it with the original cork is to trim it with a sharp knife – but this is unlikely to give you a great seal.