Nothing here travels the same way, so this is really four short guides.
Bats
A bat is long, and most couriers price on length as well as weight — long parcels attract a surcharge, and some services refuse them outright. Check what your courier does with the length before you quote a delivery price, because the difference comes off your own balance rather than the buyer's. How delivery is charged.
Wrap the blade and the handle separately, protect the toe and the shoulders, and use a long box rather than wrapping alone. If the bat is signed, keep padding off the signature itself — pressure and heat lift ink.
Shirts and caps
Fold along folds that already exist. Into a plastic bag — fabric takes damp and the monsoon gets everywhere — then into a box rather than a soft bag, so nothing presses a crease into a print or a number.
If it is signed, interleave acid-free tissue over the signature so nothing rubs against it.
Paper — programmes, tickets, scorecards
Rigid board both sides, plastic sleeve, flat box. Small paper is lost and bent in a big box.
Frames
Do not post glass. Either take the item out and post it flat, or offer collection. Broken glass in a parcel damages what it was protecting, and that is not a claim anyone enjoys.
Ink and light
Signatures fade, and sunlight does it fastest. Do not store signed items where light falls on them, and do not leave a parcel of them in a hot vehicle while you run other errands.
Questions people ask
Can I post a bat at all?
Usually, in a long box, at a price you have checked first. Some services will not take the length, so confirm before the show rather than after the sale.
Should I frame something before selling?
No. Let the buyer frame it. Framing adds glass to the journey and takes choices away from them.
What if a courier refuses the parcel?
That is a reason to offer collection on long or awkward items from the start. Per-item delivery.
More: how to pack an order, why some things are better collected.