This is the category where the right decision is often not to send it.
Decide first: post or collect
If the piece is heavy, large, fragile, framed under glass, or simply irreplaceable, collection is the honest option. Offering it is not an admission of weakness — it is the sentence that separates a seller who has done this from one who has not.
Collection is agreed before bidding, and the item carries a collect-by date. Set both before the show.
If it is going by courier
Wrap in layers, not in one thick layer. Soft tissue against the surface, then bubble, then a rigid outer. The tissue is there so nothing textured prints into an old finish.
Protect the extremities. Handles, spouts, feet, finials and corners take every impact. Pad them individually.
Immobilise. The piece must not move inside the box at all. Movement is what breaks things, not the box.
Double-box anything genuinely fragile. An inner box, suspended in filling inside an outer box, is the only arrangement that survives a drop.
Glass, mirrors and frames
Take the piece out of the frame where you can. If you cannot, tape across the glass face in a grid so that if it breaks it holds together rather than travelling into the surface it was protecting — and say in the listing that it is going framed, so the buyer can choose collection instead.
Loose parts
Lids, keys, stoppers and removable shelves travel separately, wrapped separately, and are listed on the outside of nothing. Write them into the parcel note so the buyer does not throw one out with the filling.
Questions people ask
Can I post a mirror?
You can, and many sellers will not. Offer collection and let the buyer decide whether they want the risk.
What is double-boxing?
A packed box inside a second box with filling between them, so impacts never reach the inner one directly.
What if a buyer insists on posting something I think should be collected?
Say plainly in writing that you think it is unsuitable for a courier. You are allowed to decline, and the message is the record.