Timing Is Everything
People often aren't ready to set the hook when a fish strikes, and consequently they don't hook the fish. Quick reflexes help to overcome this, but the most effective way to deal with it is to be prepared for what's about to happen before it happens. For example, generally it's helpful to keep your rod tip down when retrieving. With the tip down, you're in the best position to respond quickly to a strike, even if, as often happens, you're distracted when the strike occurs. If there's little or no slack in the line, you can make a forceful sweep up or back when you set the hook, and then be in immediate control of a fish to begin playing it.