How to ship speakers

Other than carefully packaging, what's the best way to ship speakers across country considering carrier, insurance, etc. any good recommendations?
I shipped my Thiel 3.6's in their original packaging and the buyer used Fed-Ex and they arrived safely. Worked great bc they came and picked them up at my doorstep.
How big are they? Always double box, and if they're bigger speakers [100 lbs each], I would use a freight company, and make sure that they STRAP BOTH SPEAKERS NEXT TO EACH OTHER ON A PALLET.
Always place and stick a lot of "Fragile orange sticker" aound the box provide by Fed Ex or ask the counter.If you have a lot these Fed Ex guys wiill be more carefull all the time.I shipped a lot with this easy technique and never have a problem....always insured your item sold.Good luck.
I have shipped my Zu Definitions back and forth to the factory using FEDEX ground without any problem. It is easy to track the progress online.