Tips for Reducing Shipping Supplies Cost
If the box is not the right size, consider cutting it down- rather than filling it up. This will save on weight, and reduce the dimensional weight of your package. Either way, you save money. This also reduces the amount spent on fillers (such as styrofoam peanuts, paper). Your product will also be safer and more secure if the box is a proper fit. Just make sure to leave 1-2" of space or padding around the edges of your item.
It is legal to tape together two USPS Priority boxes, as long as you are mailing priority AND they are not flat-rate boxes. This can save a ton of money on boxes. If when you are combining boxes to make a larger box, there is some overlap (flaps, for example) consider trimming these off with a box cutter. If your box is very near to the next weight (i.e. 4.05 pounds) then this will save on postage.
We recommend Seller Gear as a great source for high quality, inexpensive shipping supplies!
If you use a paper envelope make sure it is weather proof or you use a poly liner to protect your items from the elements. Many items get left on a porch, and even on a sunny day there can be sprinklers! Another precaution to take if you use paper envelopes is to reinforce the corners with packing tape. This prevents the package from getting "eaten" by postal machines and ruining the contents.
Poly mailers are a also great choice, since they are tear proof, light weight, weather resistant and fairly inexpensive. Typically the cost savings on weight over using a box will pay for the mailer!