1. The most important tip when bartering is have something valuable to barter. And that means storing up bartering items before the SHTF. The best bartering items don’t cost much before the SHTF, are easy to store, and will be worth a lot after the SHTF. See my Stuff to Store for Bartering post. You don’t want to be in a disadvantaged position, before the bartering even begins, by having little of value to offer.
2. Know the value of your bartering items. Forget about what an item is worth before disaster strikes. What’s it worth now? Do not underestimate the value of your items. The marketplace has changed, and your bartering items are not easily obtainable, and would be expensive, if available.
3. Talk up the value of your offer. Mention the difficulty of obtaining the item, in the current situation. Talk up its usefulness over anything else your fellow barterer may have. And don’t let them talk down its value.
4. Know the value of the item that you want. Do you really need that item? What’s it worth to you, compared to what you already own? Do not overpay for an item, just because you want it.