First off, thank you swtangel321 for the URLs. I have hatched using a Little Giant incubator. Probably one of the worse things one could use. My success rate has been at least 60 percent and the last one was 100 percent. I am very particular on where I place the incubator. The temperature can not vary by more than 5 degrees. I watch the humidity deligently and have made a few modiifications to the contraption in this regard.
i have since retired this and plan to use it ONLY as a temp brooder for problem chicks. I have always taken a hands on approach to the hatching process and watch from day 18 on for any signs of a peep.
I have come to the conclusion; mostly serendipously, that the eggs need to be left alone and not moved after day 19. I would say the egg carton method would be a good way to get this done. i do not think the chick needs the eggs in a pointed down postition, only that the chick has a position at all.
The humidiy is extremly important as the membrane is the thing that will allow the chick to live or die. If the chick can peep, break the egg shell, but not mak a hole in the membrane it will certianly suffocate. You can help this along by making sure the chick has a hole in the membrane big enough for the chick to breath and rest after they peep. You should see its beak at the hole and that is enough.
Most chicks will find their way out, but some need a little help and this is were one needs experience and a lot of instruction. We blindly found our way through the process and many of the things people on this site recommend is mirrored by myself.
Again, it is experience that will get you to a decent hatch. There are alot of things that happen during hatch time and the chick is the one who knows when it is time to come completely out of the shell. We take the chicks out of the incubator as soon as they are fluffed and the yolk sac cord has been seperated by the chick. It is a rare event that we cut the cord, but it does happen after we know the chick no longer needs it.
The brooder is another story and this is just as important.