Opening a bottle of Champagne with a saber can have a fairly invigorating and dramatic effect.
It's important to have the bottle quite cold. The person opening the bottle removes the foil and wire cage around the cork, holds the bottle around the base at a 30-45 degree angle, aims for the spot on the bottleneck where the vertical seam meets the lower glass lip (where the cork is), slides the saber (flat) along the body of the bottle (along the seam) towards the end of the neck. Be certain to angle the bottle away from people, food, or anything breakable, as the top will sever and head for the hills. The force of the saber hitting the bottle lip severs the glass, separating the collar from the neck of the bottle. After shooting off, the cork and collar hopefully remain together after the bottle is opened. It should sever a nice, clean, break in the glass (be aware of the possibility of the bottle shattering! Champagne sabering is dangerous and requires attention). The strength of an actual Champagne Saber or the back edge of a heavy chef's knife makes it easier, but obviously as this short footage of Karen Blackburn and Kevin Pike shows, a fork or a butterknife sometimes work, too.