BUY immediately. Sell if you are down 10 cents or more, immediately, without hesitation. Once momentum turns, get the hell out. If you're long and the stock spreads up 70 cents, going plus tick bid to an LRP, sell in the market to get that high print.
Oh, also, realize that news mostly only has two moves of easy money. If the direction you should be (long or short) isn't abundantly clear, stay out. When a stock that just ran 3 points, plunged 1.5, and is now in a 30 cent range, stop fucking trading it. The easy money is done. Don't pick tops, either, or bottoms. When the direction isn't overwhelmingly obvious, stay on the sidelines. When you think you're late, but the stock is still running or tanking, just buy before thinking about being late. Maybe the stock ran a point and has another point to go. Maybe it'll only run another 20 cents. It's much better to involve yourself than to sit on the sidelines watching a stock run two points until your mind goes "okay, this stock is never going down..." and then you buy when the stock is easy to buy. Which is the top. Always buy when a stock is really difficult to buy.