I was just thinking back on my wonderful trip. I had a few different volunteer tour guides throughout our travels. I had heard so many times that tipping is just not done and so brought with me some small packages of Sees foil wrapped chocolate easter eggs. At the end of each tour I would hand our guide one of these pretty bags and tell them it was chocolate made only in California. This always seemed to bring delight.
However, in thinking about it, I wonder if maybe on these kind of all day tours there is an accepted tipping protocol that I didn't know about. It mortifies me to think that maybe the guides were actually thinking they might get a cash tip and only received some chocolates instead.