RealityOne's method is the best, and the one that both Tamariz, Wind, and Blaine use.
With that said, if you're struggling with working with the deck, then I would recommend (if you have not done so) memorizing the deck more thoroughly (i.e. number of card to card, card to number, and in reverse order). Please don't misunderstand me, I'm not trying to be condescending or rude. I'm just all too aware of what performance anxiety can do to our problem solving abilities.
Anyways, most guys that perform with a stack can detect a card out of order in a matter of seconds. If you don't think you may have memorized the stack as throughly as you should, I'd highly recommend the "Memo Deck" phone/tablet app (Tamariz stack). It's fantastic and well worth the time and money. I'm not even kidding you, my four year old is using the app and already has the first 15 cards down inside and out.