Jackel makes some good points, but he is way off on others. First off, even great dogs lose a bird now and then. We all hate it when it happens, but I have hunted with a lot of dogs and roosters are smart enough that once in awhile even a great dog will not find one. On the other hand, you can find birds without a dog as well. The key is that you shoot them "stone-cold-dead-in-the-air". I put this in quotes to emphasize it. As Jackel says, if it hits the ground alive, you are in trouble. But, if you take good shots and use the right shells ( I would recommend #5s early season, #4 or #2 later on), you can kill roosters before they hit the ground. I don't know why most of Jackels are hitting the ground alive, he may want to consider shooting bigger shot sizes. Bottom line is this, take good quality, close shots and shoot twice if it is obvious the bird will be alive when it hits the ground.

As for hunting, hunt strip cover and places other hunters overlook. You know that little 20 foot by 30 foot low spot 1/4 mile from the road in the middle of the field? Nobody else would walk all the way out to that for a 3 minute hunt, but you should. You will strike out some, but you may walk into 20 birds in another. Plus, these birds will probably be easy to find. Remember to hunt these spots like you are hunting deer--sneak to them. A wary rooster will fly when you are 200 or more yards from the spot. Early and late and mark birds when they are moving and then go get them. If you can find a good feeding area, they will be coming back to the roost just before darkness. Setup an hour or so before dark and wait for them to fly into roosting cover. When they do, mark them and go get'em. Always try and pinch a rooster into something (short grass, plowed fields, a creek, a road, etc). Always stop 5 yards before you exit cover and wait. Take 5 steps to your right. Wait. Take 10 to your left. Wait. Sometimes that will work. Good luck.