Nothing. I've considered keeping cigarettes for barter, but never did anything about it, partly because as a non-smoker I wouldn't know what to buy. And I don't know how well they age. Their virtue is that if smokers run out they might become desperate for them.

The best trade items are probably irreplaceable consumables (which means most consumables nowadays). People are going to run out. The maxim, "Buy what you eat, eat what you buy" applies; it's best to stock the consumables you yourself consume.

So I have strategic surpluses, goods where I keep way more than I expect to need. I suspect they'll get given away rather than traded, which you can think of as bartering for goodwill.