I have had the best results with a double lung pass through low in the chest. Again, I emphasize, LOW in the chest. Many poor blood trails are simply a case of the body cavity filling with blood and nothing coming out of the wounds. Simply aiming lower will help get all the blood trail you need with most any quality broadhead. Most deer are shot from an elevated position so the exit wound is typically lower than the entrance. That is why the pass through is so helpful in making a better blood trail.