I prefer not to have a caddy, but a couple of my golf buddies like to go to decent courses and use caddies. Depending on the level of satisfaction with the caddy, I typically tip a little over half of the price of the caddy. Often, if I get an older, experienced caddy, I will tip a bit more than I would tip a kid... but that is because the older gentleman is usually more knowledgeable and gives great advice (i.e. the greens generally slope towards the mountains on this course). Generally you will walk with a caddy (exception for some forecaddies). Also, seeing that the course you will be playing will have caddies, I bet they will also have bag drop attendants, club-cleaning teens, and cart-cleaning folks. At some courses, these folks expect tips too.