1. Keep the Game Moving
2. Do Not Bend the Cards
To keep the game moving we use two decks of cards. When one deck is in play, the other should be shuffled. This process saves time and allows all players the opportunity to shuffle the cards.
After a deck is shuffled, it is cut by another player. In a proper cut, the top portion of the deck is pulled from the deck and placed on a plastic card cover. The use of the card cover prevents players from seeing the bottom card.
In order to prevent bending and premature wear of the cards, use a casino style shuffle known as a table riffle shuffle. The cards are placed in two piles. Each pile is fanned by the thumbs. A more detailed description was found on the Internet and is republished below.
The Table Riffle Shuffle
This shuffle is also quite common. You can see it in every casino.
At the beginning the deck should be on the table with the longer side facing towards you. Cut about a half of the cards and place them next to the rest of the cards that short sides of both packets touch each other. The right hand is placed on the right packet that thumb is in the left corner of the deck on the side facing towards you, the index finger on the top of the packet in the middle of the short side close to the edge and the rest of the fingers are on the longer side of the deck opposite to you. The left hand is placed on the left packet in mirror symmetry with the right hand.
Now rise both thumbs a little and at the same time apply a little bit of pressure on the top of the deck with your index fingers. Release the cards from both packets with your thumbs while rotating both your hands so at the and of the shuffle (there are no cards held by thumbs) the angle between the two packets will be instead of 180° ca. 160°.
Now you have to insert both packets together. Again there are different methods how to do this. E.g. curl your little, ring and middle fingers and place them at the short sides of the packets, your index fingers on the long sides of the packets opposite to you and the thumbs on long sides of the packets facing towards you and now insert the packets together and square the deck.
When you start practicing this shuffle you probably won't be able to make a perfect riffle shuffle (the cards are released one by one so at the end there are no two cards from the same packet together) but after a few days of practice you'll be able to do a decent riffle shuffle.