Relinquish the schedule and see what adventures happen.
"To reduce travel stress, plan less." The moment I saw this headline in the New York Times, I was jumping up and down in my seat in agreement. The advice might sound totally counterintuitive, but there is valuable wisdom in it. Hear me out (inspired by Geoffrey Morrison's great article).
Unless you've already stayed somewhere, it is impossible to predict what your accommodations will be like. Online reviews offer a limited perspective, and who knows how much has changed since they were written or how different personalities interpret different spaces. All this is to say that you cannot accurately gauge comfort, cleanliness, location, value, and food until you've arrived – and then there's a chance you won't be happy.Do you want to be locked into a prepaid, non-refundable arrangement for the rest of your vacation? Or would you prefer to be free to move on, to check into a better or cheaper hotel you spotted elsewhere? This is why you shouldn't book anything more than a few days in advance. Two or three nights give you plenty of time to get your bearings and figure out if it's where you want to stay.
This is how I always travel, even when I'm with my kids. Sometimes I don't book accommodations until the morning of, because I don't like to be locked into plans. I don't know what train I'm catching, what delicious meal might delay me, what the weather's going to be, what interesting landmark someone mentions in passing that I have to check out. So usually I plan the first 1-2 nights and the last night, and leave the rest open to fate.
This creates glorious opportunities for adventure. It means you can meet people and become instant friends and tag along on outings you wouldn't have been able to do otherwise.
I apply the same philosophy to my days, upon arriving in a new city. I do as much reading and research as I can in advance, but then I let each day determine what its activities will be. This allows room for spontaneity, mainly in the form of new local acquaintances who invite you to do things and to which you should almost always say "yes!" (after consulting your creep-o-meter, especially if you're traveling alone).
There are a couple basic things that make this approach to travel much easier, and that is having reliable access to the Internet and packing lightly. The former is obviously required to make last-minute bookings, whether you do it through apps on your smartphone or travel with a laptop, as I do for work. If you are going somewhere without a reliable Internet connection, then you should make plans in advance.
Packing lightly is an enormous help as well, because it allows you to move easily between places. You don't think twice about switching hotels, beaches, cities, or even countries, nor hopping on public transit or boats or road trips, when you're wearing a backpack; but add a couple rolling suitcases and you've become a burden on the world. (I've written several posts on this topic; see related links below.)
I realize this spontaneous approach isn't for everyone, but I do urge you to give it a try, if you haven't. It's empowering, freeing, and utterly exhilarating to show up without a plan and see where you end up.