Cooking with Gas

Those who fail to learn from reality TV are condemned to repeat it. One of the thrills of a long-running reality competition like Bravo's Top Chef is seeing which contestants end up making the same old mistakes. As we go into Season 6 (debuts Aug. 19), we've now seen enough aspiring top chefs rise and fall like soufflés to offer some hints for the competitors.

1. Do not rely on the freezer. Because it will break your heart. In season after season, the freezer door has been a gateway to icy-cold disappointment. Or, often, insufficiently icy-cold disappointment: gelati that fail to...