I am a widow and seriously poor now. That's why I'm asking what is good for trading. I don't want to leave something that would offend anyone.
My swag bag contains all the weird things that were sitting around my house. Keychains, pins, foreign coins, happy meal toys, stuffed toys, hotwheels cars, army peeps. All sizes of things because caches come in all sizes.
I do my best to load up caches so that when families come to the cache with young ones, there are cool things to sort through and choose. That way the young want to get outdoors and go caching again!
Every once in a while, rarely, someone will leave a geocoin as swag or a FTF (First to Find) gift. But that is fairly unusual. Usually Geocoins in caches are travelers just like travel bugs that need to be moved from cache to cache.
Have fun! This is a wonderful hobby!