Assuming you're in the US, here's what I've done. This works for books as well.

Get a flat rate Priority Mail box. Assemble it but don't seal one end. Put in your item, enclose a roll of tape for them to seal the box (because I don't trust those boxes to seal properly on their own.) Print out postage from your computer, addressing the postage label to you and from you. Put on box. Gently close the box with two pieces of transparent (not packaging tape.)

Write a nice letter asking for what you want. Put that in an envelope addressed to the person with a "open box here ---->" written on it.

Get a roll of wrapping paper. Dollar store paper works. Place the box so that the blank side of the wrapping paper is up. Wrap and tape like a present.

Address the box. Bring to Post Office.

This way, all the person has to do is rip off the outer wrapping, open the envelope with your instructions, place the item in after its signed, seal it with your tape, and either drop it in the mailbox or hand it off to someone at the Post Office or their carrier.

I needed a new jersey anyways

Rule #1 for TTMs.... Don't ship anything you don't want to loose.

Just a heads up... You are taking a chance you'll never see your Jersey again.

what I have done is get a box that would fit your item to ship. print your label that is going to that person and print a second label addressed to you. next go to the post office get the have them put postage to ship to them and ask the postal employee how much to ship back to you. then ask for that amount in stamps so you can put it in the box with your letter/ return shipping label and the postage. hope that is helpful
jaime

I am going to ship a jersey to Dirk Nowitzki for him to sign and I have no idea what to do. I have never shipped before in my life and I have no idea. Can anyone tell me what to do?