Since card handling is an important skill in euchre, we here at the Euchre Universe constantly search for new ways to manipulate the pasteboards. While stumbling around the web (literally) I came accross this nifty description and video of how to cut a deck one handed.
And if you want to see a video of it in action, check out this one over at Youtube.com. The second version in this video is known as the Charlier Cut and it's the one I most often use.
While you're at it, you might want to learn to just shuffle a deck of cards one handed. This will take a bit more practice than the cuts. Here is a video version that is pretty good.
But all of these card handling skills will be useful for intimidating your opponents at the euchre table. And since euchre is a game with a significant amount of luck, any edge you can get over your opponent is worthwhile.