Some times you just find a canister with a sign in book, most of the time you will find little trinkets. I came across several cameras to take your picture then leave for the next visitor. At some point the cache owner will come back and replace it with a new disposal camera.
One thing I found, and started doing myself, is to put dog bones in the more active sites. Allot of people bring their dogs along and it’s a nice treat for them.
Some other things I found:
Part of the fun is deciding what we’re going to take with us to put in the cache we find.
Geocaching is a blast! Most of the fun is in finding the cache in the first place, and lets not forget the exercise you get from walking and climbing.