Salience

Make your items salient so that wandering traders will find and offer them back to you!

Craft a salient bottle by combining a bottle, a honeycomb, and an amethyst shard in a crafting grid.
To use the salient dust bottle hold it in your main hand and the item you wish to make salient in your off hand. Them press your "use" button (right-click by default).
A salient dust bottle has five uses after which the dust is all used up and only the bottle is left.

If a salient item despawns it can be recovered by a wandering trader who will offer to sell you the item back for some emeralds. An item can only be recovered once so if you don't buy the item it will be gone forever.