The Discard: Using "Sluffing" to Your Advantage
Dumping Your "Bags"
If your team has already made its bid, every extra book is a "bag." Use a high card (like a King of Diamonds) to "throw off" on an opponent's Spade lead to ensure you don't win an unnecessary book.
Nil Protection
When your partner bids Nil, you should "sluff" your highest cards as soon as possible. This ensures you won't be forced to take a book later that your partner might have been able to duck.