I dry incubate, 20% or less humidity usually, don't turn for the first 3-5 days, after that turning is important for proper blood vessel development IMO. and I hatch at 55-65% in egg crates so the newly hatched don't scramble their hatchmates.
I got into hatching shipped eggs nearly a yr ago. I started off doing it just like the incubator instructions said and that was to have the humidity about 45 to 55 % all along. when the eggs were about one wk from hatching, I was comparing the air cell size to those pictured in that hatching 101 thread on here and realized that my air cells were still nearly as small as what is normal for eggs only a week in incubation. My eggs hadn't lost enough moisture. I had to take out all water and turn up the heat slightly to get those air cells to the right size before hatching.
Like ki4got, I am now a dry hatcher. Dry hatching has been especially important in hatching darker shelled eggs like the welsummer eggs. Those eggs don't lose moisture easily and without dry hatching, I do not get many of those to hatch. I think weighing the eggs at beginning is very helpful. Lighter colored shells and shells that are porous will lose moisture more readily, maybe too fast if your dry incubating humidity is consistently really low. I am dry incubating right now and it's staying about 20 to 25% but in summer when outdoor humidity was very low, I had it go down to like 15 and SFH eggs, I found, are some of those that lose weight more easily. In my case, humidity that low was causing them to lose weigh too fast and I did have to add small amts of water at times with those to bring humidity up a bit. This is when the scale was so helpful to monitor everything
As for what is helpful for shipped eggs specifically, I do let them rest 12 to 24hrs with lg end up before putting in incubator. Eggs that look the worst get the most rest time. With shipped eggs I don't incubate on their side. I put them in an auto turner but wait two or three days before I let them begin to turn.
I read about hatching in cartons and it sounded like a great idea but I had one very valuable chick try to pip small end, where the egg was up against the carton. That chick was trapped and by the time I realized what happened, the chick had died so I don't do cartons anymore. I do get crazy when hatching chicks are banging around the unhatched eggs even though others say it's just fine. In a nest, eggs wouldn't be rolling all over, hitting each other. I will make little "corrals" with paper and put a few eggs in each and that helps limit the area that they will roll around in.
I know we are not suppose to open the incubators in "lockdown" but I had instances were eggs were being too harshly knocked around or had newly hatched chicks get stuck upside down and other chicks would start pecking at it's delicate abdomen. I couldn't wait to see if the new chick got eviscerated! I had to get chicks out. I got one of those hand held clothes steamers from
walmart and when I want to remove chicks while others are still hatching, I open, grab chicks quick and give a puff of steam into the incubator before I close. That steam is pretty hot so I take care not to shoot it directly at the chicks or eggs and not release it really close but it has allowed me to open the incubator for removing chicks while others are still hatching.
