If you will be doing a lot of shipping, set yourself up to buy postage on-line or get a postage meter service. You'll save yourself from frantic trips to the post office or having to wait in line. Set up an account with an overnight shipper. It costs nothing to set up. They will provide the supplies you need and you'll be able or order pick-ups, print shipping labels and track deliveries right from your office. You will be billed periodically for the shipping you do.