Since I both buy and sell hatching eggs, I would say to make sure the shipper does the best possible job of packing the eggs for their journey. Even so, don't expect more than 50% of the eggs to develop/hatch. If you get more than that...GREAT...they probably had an easy journey to you.
If you have less than that, please don't blame the shipper unless you had eggs arrived poorly packed. You cannot get insurance on the eggs, so start with less expensive eggs until you get a feel for hatching.
If you have shipped eggs that don't develop, please don't assume that they were NOT fertile. Just because they are "clear" and don't develop does NOT mean they weren't fertile in the first place. Shipping takes it's toll on them in many ways...broken aircells, scrambled yolks, just to name two.
Notify the seller if you have a poor/none hatch. Many sellers will work with you to get you more eggs for the price of shipping. If you know you had incubating issues, take your licks and purchase more eggs. Don't ask for replacement eggs.
Agree with other posters...make sure you have seen pics of the parent stock so you have an idea of what to expect from your chicks.
The general consensus is to let eggs rest large end up for 24 hours before placing them in the incubator to allow the aircell to stabilize. There is no science for this, just common sense. I have placed them in the bator within 6 hours of arrival and had great hatches.