Watch the prices of everything, housing, stocks, commodities, energy etc. Also listen to the news, at the point when every talking head, and all your friends tell you not to buy something because the price is going to be down forever. That is when you buy it.
Irrational fear is what you are looking for. When everyone else is afraid, you need to have courage and buy into the market everyone else is running from. Then when everyone else is buying back into that market, and you can’t turn you head without hearing about how great it is, sell.