I’ve been on several long international vacations, and scheduling anything goes against my style completely. I hit the ground and then see what’s what. I do tend to plan road trips, but nothing more than ‘drive to this place on this day and then this place on the next day,’ etc.
One time, I went to the Costa del Sol in Spain for 10 days with a couple of friends, and we all agreed to research a couple cities along the way, and split up the work. They planned their days pretty hard and fast. I tore the pages out of the guidebooks for the cities I was given, and let inspiration strike.
I think in that trip, I broke rule #2 (“Think about your personality and who you’ll be going with.”), because the two type-A women I went with weren’t initially very happy with my type-B kind of planning. But it all worked out in the end. (Though, come to think of it, one of them never spoke to me again.)