My family is probably one of the epitomes of no planning. In fact, this trip we're taking in less than a month is the first time we've ever really made ADRs and FPs prior to leaving for the trip!
We're a family of 6 (my parents are currently 51 & 50 and we four children are between the ages of 19-24) who have been going for years with the high school band (every other year since 2009). That was part of the reason we didn't plan anything, though. We knew what day we were going to be in the parade and only planned that day. For the others, we literally woke up in the morning, looked at the some app, and determined which park looked like it had the lowest wait times. I don't remember what app my siblings had used before, it may not have even been the Disney one? I'm not sure but it like had the parks color-coded as to which ones were predicted to be the lowest, so we went there those days. It may not have even been an app, they could have Googled something.
My family also went during the time of paper fast passes, but we still never grabbed any, except for like one or two over the course of the entire trip. We did the rides we knew we liked and just moved on. This actually allowed us to experience different things each time. We actually didn't even really see some shows until last year, like Fantasmic or Mickey's Philharmagic. We shifted our focus each time and were able to discover something new just by simply wandering over to something and deciding to try it out.
We also had never done an ADR before. Well, we did one but it was very spur of the moment, like walking up and asking if it'd be possible to eat there. We always ate breakfast and then maybe grabbed something at a place that seemed interesting for lunch in whatever park we were, and dinner was typically at like 11pm, as in the case with our last trip, at the hotel or at a QS in the park, depending how late the park was open.
It was basically us just doing what we felt like when, with no schedule and no place to be. We got up in the morning and hoped to leave between 9-10 with no real time set to hope to return by. We did a lot of things spur of the moment because they looked interesting and probably spent a lot of time at things people might think are "unnecessary" because we thought that they were interesting and wanted to see more.
I say, just go with however you feel that day and if you need to plan, plan for the things you know you like. But if things seem interesting, things you didn't even know were there, then go ahead and try them, you might find something you truly enjoy and want to do again!