We are going to do OOT bags and are expecting between 40-50 people, but I am only getting one bag per couple/room and not each individual. Each bag will have 2 tumblers so everyone will get one of those, but as for the other stuff only one per bag like a lanyard, think we are going to burn a Bob Marley CD since we are getting married in Jamaica. Also going to throw in some disposable shot glasses as there are liquor dispensors in the rooms, and maybe a cheapie dollar store inflatable raft. Overall so far these will only cost me $7 a bag including the bag itself! I will probably throw in some of the other stuff too like Tylenol packet and some snacks. But definitely planning to keep it between $10-$15 a bag.
I am not doing any favors other than this. I don't think you need to do anything really, but it is a nice gesture. And an excursion would be just as nice as a little bag of stuff!