On the other hand, nothing will spoil your poker-face faster than a clumsy shuffle. Banish the card-randomizing blues by learning how to shuffle properly.
Mastering the Riffle shuffle
The Overhand shuffle, the Weave shuffle -- there are lots of cool ways to shuffle cards, but the only one you absolutely need to know (and should learn to master) is the Riffle shuffle. Here's the gist.
Split the cards into two roughly equal halves. Hold one stack in each hand, with your thumb at one end and your middle and ring fingers at the other. The stacks should face down, for obvious reasons.
Rest your index finger against the middle of the back of the stack, and use it to gently bend them downwards. Don't do this with that heirloom pack of cards that's been in your family for ten generations, incidentally: practicing is going to wear them out pretty fast. Use something disposable.
Put the stacks side-by-side, and raise your thumbs gently, so that the cards "riffle" inwards and mesh together. Once they've all fallen, don't move your hands -- just pick up the newly randomized stack, and bend it gently upwards in the center. Once you get the tension just right, relax the fingers that should still be holding the cards from underneath. The cards should riffle together a second time, squaring up the pack and producing a most satisfying "thrrrrrp" noise.
Mess up? It takes practice to get just the right amount of flex -- too much or too little, and they'll either go nowhere or all fall on the floor. Don't try to go too fast at first, although once you get the technique down a riffle shuffle should work in just a few seconds. It's easier to learn with a slower, more deliberate pace, however. And if you're really having trouble, try putting the cards in a zip-lock baggie with a little talcum powder and shaking it up well: the talc will help cut down on friction and make the cards slide more readily.
Once you've got your technique down, don't make the mistake that one shuffle is enough. Magician, mathematician, and Stanford professor -- how often do you see those words together? -- Persi Diaconis proved in 1992 that you need at least five riffle shuffles to produce an acceptably randomized deck, and seven is better. One ain't gonna cut it.
Which brings us to the next step, the cut...and although you can do it the boring, old-fashioned, put-it-on-the-table way, that's not going to intimidate your poker buddies like a good one-handed cut. It's not as hard as it looks, but it isn't that easy either.
Here's a particularly killer cut, which will invariably take a lot of practice but will be well worth the astonished look on your friend's faces. You can also upgrade to fancier shuffles, like the impressive Hindu Shuffle, or showcase your inner James Bond with that flashy card "spring" move that's in every Hollywood casino movie ever made.