I don't put decks in the refridgerator. I don't use powder to clean decks. I don't alternate decks that I'm using. The best advice is to wash and dry your hands before using a deck. The reduces the dirt from your hands getting on the cards.
Other than that, decks are disposable. The main factor in how long they last is how much you use them. Most of the use for decks is in practice. I use new decks for performances and older decks for practice. As the old decks get unusable, I start practicing with a performance deck and open a new deck for performing.
Truth spoken. You don't need to get crazy buying special powders or refrigerating paper. Heck, the thing that will kill a deck faster than just about anything else is humidity, and you encourage humidity by forcing the decks through sudden temperature changes. Not worth any perceived benefits.
Find good, cheap, every day cards. For me and most magicians out there Bicycle decks are the best for this. They are super cheap and they are available all over. Use that deck (washing your hands is great advice for keeping your decks in good condition for longer). If it starts to feel too soft or if the cards start to stick, open a new deck. Simple! Don't throw away the old deck, let it sit in a cool dry place for a while. If it was getting sticky due to humidity, giving it time to dry out from your hand's moisture will bring it back to a usable condition. If nothing else, you will have spare cards to use. Save your nice cards for when you want to make an impression.
If you carry cards in your pocket, invest in a good card clip. It keeps the cards from getting warped and bent when in your pocket. It will extend the life of your tuck case and the cards.
// L