Most common cheating by casinos today...
does not involve sleight of hand. It is the preferential shuffle, in which the casino gives deep pen in bad counts, and shuffles early in the good counts. This is cheating because they are denying even the ploppies random cards. They are instead playing negative counts much more often.
As far as the sleight of hand stuff, not much goes on in major US casinos. I believe if it does, it is usually collusion between a dealer & a confederate player without the casino's knowlege. Just watch the top card and the dealer's thumb on the top card in pitch games. Often the dealer will slide the top card out slightly between hands and either peek or flash it to the confederate while straightening up the tray or going to the discards. They will either cock the deck substantially or have a reflective surface to pass it over to get the peek. As they deal, watch the thumb & markings on the top card and see how they move. To deal 2nds, the thumb will slide the top card back towards the dealer slightly instead of pushing it towards the player, and the card markings will not move. Watch for a dealer not covering the bottom of the deck with a cut card and for unusal grips as well.
Other than pref shuffle, I wouldn't worry about cheating too much unless you play for high stakes. Casinos simply have too much to lose if caught, and will not expose themselves to that risk for a few bucks. I have only seen one case that I thought was casino endorsed cheating (again, other than the common pref shuffle). In that case the dealer peeked at the next card near shuffle time and if it was a good card, he shuffled. If it was a bad card, he dealt one more round, giving the bad card to the player.
