How to Pack and Ship a Guitar
A guitar should always be shipped in a hardshell case and the strings should be loosened a full step down from standard pitch. This will help support the neck and headstock without unnecessary tension.
Remove all unnecessary items from the case that don't need to be shipped (capos, cords, etc.) and place anything that must ship with the guitar (strings, parts to be installed) in the accessory compartment. If the item(s) won't fit there, you can pack them in a small box inside the large box that will ultimately house the guiitar case.
Place the guitar in the case and fill any air space with packing material. Crumpled newspaper is inexpensive and provides excellent shock absorbtion. If you don't have any, use bubble wrap. "Shipping popcorn" is a nuisance to handle. It also leaves little crumbs in the felt of the hardshell case, which has to be vaccuumed out. Make sure that any unsupported areas of the guitar are supported with the packing material, especially around the headstock. to prevent the neck from shifting around. Fill the space behind the neck and anywhere else, like the "waist" area, to keep the instrument from moving around in the case.
You should also put some folded paper between the strings and the fingerboard and pickups. If you are shipping an archtop, put some crumpled paper between the strings and the body, around the bridge.
For an extra measure of protection, put the case in a large plastic bag before putting it in the box. This will keep water out.
Get the strongest guitar shipping box you can find, ideally measuring 8"x20"x50". A local music store may still have one that hasn't been disposed of. This box should have 2" to 3" of space on all sides between it and the guitar case.
Stand the box up and put an inch or two of packing material (crumpled newspaper or bubblewrap) in the bottom. Place the guitar case in the box, bottom first and centered. Fill all spaces between the box and the case completely, with the packing material, right up to the end of the neck part of the case. Put a small cardboard box on each side of the case neck to keep it centered and stiffen the entire the entire package. Fill up any remaining spaces with packing material, all the way up to the top of the box. Make sure that no part of the case is touching the box.
Your guitar now has two layers of shock protection, one in the case and another in the box.
Tape the box shut with some strong shipping tape, sealing all the seams against wet weather.
In addition to the "from" and "to" addresses, print in large letters on bith big sides of the box "FRAGILE - HANDLE WITH CARE".
Insure the instrument for at least it's replacement cost, and record the tracking number, just in case you lose the receipt.
DON'T SHIP A GUITAR WITH THE US POSTAL SERVICE if you want to be able to track your shipment. Every time I have shipped with them, the tracking number on the receipt was not recognized by their own computer system! On one occasion it took them three weeks to deliver a package a distance of 80 miles! I had insured it for full value, but It showed up at it's destination on the day the insurance was claimable (a period of ninety days). Fortunately it was not a customer's guitar, just a part being returned to the supplier.
By packing and shipping your guitar according to these instructions, it should arrive undamaged, and you will be able to sleep well.
When you receive your guitar or bass, it should be allowed a couple of hours to adjust to it's new environment. Temperature and humidity play an enormous role in the performance of wooden musical instruments, and traveling exposes it to several consecutive changes in those conditions. It is best to place it in the location where it will be played most, outside of the case, and come back in two hours and start playing it. This will reduce the tuning process.