I go to the sight of the shot immediately. What I find there determines how quickly I follow. If it's obviously a good shot, i.e. bright lung blood everywhere, etc, I follow immediately and usually find the deer piled up within a few yards. If it looks like it might not be a good shot I wait about 30 minutes, fortunately I haven't had to do that very often. 99% of the time I follow immediately, that's assuming the deer isn't piled up within sight, which it usually is.