Editor's note: This show last aired on Nov. 28, 2008. On Wednesday's "Mad Money" TV show, Jim Cramer continued filling viewers in on the methods of his madness -- all the little tricks and tools he uses to pick stocks, to know when to buy and sell, and generally to be a great investor. He started off by giving people a "rainy day" tip for when the market is having a really bad, down day. "What you need to be looking for after a down day is buying opportunities," Cramer said. "There is no better opportunity to buy than when you find a stock that's been upgraded by some analyst on a down day."