Do not use any printed paper like newspaper as it could bleed in transit and stain the case. Do not use a thin box as it can easily puncture or loose its structure and make sure you have the right kind of thick tape that will not come off during the trip.
Now sit back and relax knowing your guitar is on its way and you have packaged it like a professional. You now know how to ship a guitar in a hard case. If you have any questions regarding shipping you can reach out to email@example.com and we can assist you with any questions you may have.