I only had 2 cracked eggs in the hundreds I shipped last year...I individually wrap them with bubble wrap pouches - they have an adhesive strip on the end and they work SO well. I do not put in cartons, but I am not opposed to that. I also do not double box. I used to do that, but found it only added extra weight and didn't seem to help the eggs in any way. I put 3-4 layers of large bubble wrap in the bottom of my box, then wrap each egg in their individual bubble wrap pouch (which also would keep any mess inside if one WERE to break, so as not to contaminate the rest), and put them fat end up, surrounded by peanuts. I put however many layers of large bubble wrap are needed on top, and sometimes will add an opened up egg carton on top, just to take up space. As indicated, I only had 2 cracked eggs last year in all that I shipped, so I'm sticking with this method.