I have come across an interesting article about how to prepare your artwork for shipping. As it also presents the way I go about it reasonably well I thought you might want to take a look. It shows that careful packaging not only ensures the goods will arrive safely at your customer´s but it also reflects on your approach to quality.
A well presented parcel is the fist impression your customer will get when the parcel is delivered to his door. So it is best to make sure that your art arrives in a neat and tidy package with no chance of any damage to its contents. You never know your customer might tell a friend and you might get another enquiry.
If your artwork arrives in a sorry state you will certainly get complaints and your customer will never buy from you again. Instead he will tell all his friends to steer clear of you.
So here is the link to the article.