Sabering champagne is an impressive way to open a bottle of bubbly and it's way less intimidating than it sounds, especially when you understand the dynamics behind the process. Icing the bottle upside down forces the carbon dioxide into to the neck of the bottle and working at the seam takes advantage of the weakest part of the bottle (the point where the seam meets the lip). You may need a few tries to get it right, but with a little practice, you can be swashbuckling with the best of them. If you have a sword, you're set. If not, a butcher's knife will work just fine.
Chill a bottle of champagne for at least two hours, or until it reaches about 38 to 40 degrees F. Resist the temptation to skip this step. Glass is more brittle and easier to break when it's cold than when it's at room temperature.
Transfer the bottle from the fridge to a bucket of ice, and place the bottle upside down into the bucket. Allow to chill for 10 to 15 minutes.
Remove the foil, and then the hood (wire cage) from the bottle.
Point the bottle away from yourself and away from anyone or anything that could be hurt or damaged by the flying cork.
Inspect the bottle, looking for the seam running from the lip to the base. On some bottles, you'll be able to see the seam fairly clearly but on others you'll be able to feel it better than you can see it.
Hold the bottle in your non-dominant hand. Turn it until seam of bottle is facing up and centered.
With your dominant hand, hold the blade about a 30-degree angle, near the bottom of the bottle, resting against the seam. If using a knife or sharp sword, point the blunt edge toward the cork.
Slide the blade down the bottle, toward the cork, smoothly and with a modest amount of force. Let the laws of physics do the work for you. Aim for the lip of the bottle, not the cork.
Push through the lip of the bottle. It should burst forth, taking the cork along with it.
Retrieve the cork and check the surrounding area for shards of glass.
Pour and enjoy!