Be on the lookout for instances where the short terms moving average crosses over the long term one. For example, when a stock price crosses the 20 period moving averages, and then the 50, while the 20 then follows the price, would be a good area to short. Note that bounce backs towards the 20 period moving averages would then act as areas of resistance, and could offer more short selling opportunities. Once again, be on the lookout for big volume with price declines to confirm a down trend.