Purchase your shipping supplies from a packaging wholesale company. Most of these companies sell shipping materials at lower prices when you buy in bulk.
Take advantage of USPS’ Priority Mail service when possible. You can send any item domestically at a flat rate regardless of weight as long as it fits the box and does not weight more than 70 lbs. Priority Mail boxes and envelopes are available for free from the post office or you can order them at www.usps.com and have them delivered at your doorsteps.
Shops selling the same items you plan to ship are great places to get free boxes and shipping supplies. For example, if you are shipping a bike, ask your neighborhood bicycle store if they have boxes that are lying around. These shops just usually discard boxes where their merchandise came in and most are willing to give them out to whoever is interested for minimal fees or even for free!
Only reuse or recycle boxes that are clean and sturdy. The box should be rigid enough to protect the item inside from falls, bumps and from other heavy packages that may be placed on top of it during the course of shipping.
Avoid boxes that used to contain prohibited or regulated items such as liquor or hazardous materials. The labels and markings on the box might be cause for problems in the post office or shipping company. If you opt to use them, you might want to remove any markings or labels that indicate its previous content. Alternatively, you can invert the box inside out or wrap the entire package in shipping paper to cover any marking that may cause delays.
Another great place to get inexpensive boxes is at packaging recycling businesses. These businesses buy used and unneeded cardboard boxes and sell usable ones cheaply. Check out your local yellow pages for recycling companies in your area.
Save on gas and effort by having you packages picked up instead of taking them to the post office yourself. Simply call your local post office or parcels service to ask for delivery and pick up schedules in your area. Be reminded though that pickups require certain size and weight restrictions. If you go over the allowed package weight or size, you will be charged extra fees.