When Wilson and I traveled this summer there were a few different technics we used. One was looking up things to do and planning out every step of the way and the other was just leaving it up to where adventure took us. Both were really fun, but they both have their pros and cons and I will tell you those now.
Pros of Research: You don't miss anything, you see everything you plan to see; you have a pretty good idea of how much money you will need to save; you have an idea of where you're going and how you are getting there; and generally, you will know more about the things you are seeing.
Cons of Research: You feel bad if you don't stick to the schedule (at least I do); you don't have very much spare time to see something you maybe didn't plan on; and you might be disappointed if something isn't exactly what you had in mind.
Pros of Adventure: You have the thrill of the unknown; you aren't limited to a schedule; you are okay if the plans change; you are surprised; and you have no real expectations that can be disappointed.
Cons of Adventure: the border guards might be both confused and not easy on you; you have no idea what to expect; you might miss things that you later regret not doing or seeing; and you might feel stressed about what you're going to do.
I recommend a mixture of the two, I personally had more fun on the trips we didn't plan out because I love adventure and leaving things up to how we feel that day, but that isn't ideal for everyone. If you plan a couple things and leave the rest to the unknown, you get both experiences. Let me know what you have tried and enjoyed in the comments below.