Make it an adventure! Go exploring!
Do some advance prep, then go with the flow – some of the best adventures are planned the night before.
Oh, sure, I buy the guide book. Sometimes more than one (I’ve got two about the Camino right now), but I use them like an encyclopedia. That means I get some “must see” ideas in my head, then go out and explore, referring to the book to fill in the details. It takes a little practice, but it’s really nice to leave the written plan and itinerary behind and explore.
And for gosh sakes, learn to travel with one carry-on size bag and a “personal item” (camera bag w/computer or computer bag with camera). You can check the big bag if you want, but it slows you down if it’s lost.