My general mantra when traveling is to avoid ALL guided tours, by any means necessary. There are times when they’re easier and definitely more convenient (if more also more expensive), but I like the freedom to follow my own schedule.
Which is how I ended up on an overnight bus to Uyuni with loose plans on what to do when I got there:
1. Find someone to take us on a 2-day tour of the salt flats.
2. Go on said tour.