There are 3 categories of needlepoint when it comes to shipping options.
The first is the unstitched canvas. It should be rolled and placed in a tube or kept flat and placed between 2 pieces of cardboard or if small flat in a padded envelope. As a last resort, fold it. Some people are quite particular about the canvas not having been folded. It actually doesn't affect anything and will disappear with stitching, but if it is a concern, merely press the back of the canvas with a steam iron to smooth things out. After all, canvas is just a combination of woven cotton threads that are heavily starched with then a painted design applied. Also, I almost forgot, put everything in a plastic bag, whether a trash bag or a ziplock bag.
The second is the stitched, unfinished canvas. Again, place in plastic and cardboard. Whether you ship flat or rolled or folded entirely depends on the stitches and embellishments used. Rolling or flat are usually preferred, but always in cardboard. Never in a padded envelope. I've had people fold a stitched belt and mail it to me in a regular envelope. Dangerous! You only have to see one envelope that has been caught in conveyor belts to never try this again.
Lastly, we have the finished product. I always ship in plastic in cardboard. I also always insure for $300. via the US post office which necessitates that the recipient must sign for the item. I've had one or two postal clerks tell me that $201 in insurance calls for a signature, but others contradict this. Just to play safe, I always purchase at least $300. in insurance, though for Christmas stockings and pillows I increase the insurance. I stress to my customers that this is my method of shipping, but it amazes me the number of people who do not hear me say that someone must sign for the package. Otherwise the postal carrier will not just drop the package on the doorstep. They do leave a printed slip advising that the item can be picked up the post office; or, I think, can be redelivered upon the receipt of a phone call to a stated post office phone number.
I received an email Monday evening from the owner of a Christmas stocking that just made the finishing deadline. After a few hours of angst on my part (since I have shipping records at the shop, not at home) and after I emailed her to try the post office, she emailed that it was waiting for her at the post office. Sigh. Similarly, I received a phone call at the shop today about 3 creche figures that I mailed to a stitcher's daughter the end of October. After several phone calls, I found out that it is indeed on a back shelf (one assumes since it's since October) at her daughter's local post office. The post office officially states that after a certain period of time they will return the item to sender, but don't specify a time period. In my experience, it is never. You have to take the initiative and hunt the item down! Like the trunk show I returned to Whimsey & Grace this past year. Somehow its zip code was entered incorrectly by the postal clerk and it arrived in Alaska. It was then placed, literally, on a slow boat to the "mainland"--which took 3 weeks--before it arrived at its original destination. If I hadn't already had gray hair, that would have produced some!!
Almost forgot--I hope everyone has and has had a joyful holiday season!!!