We visit the World once every two years, so I need to do a little planning! Basically I follow the boards to see what's new, what's closed, what I might not know about. We don't buy hoppers, so I look at the park hours to see which park on what day we will want to visit. We often stay offsite and don't do the
ddp, so I make an adr for a couple of must-do restaurants (Boma, Kona) on the days I know we will be going to those parks, but as they are resort restaurants, that's not really necessary, just convenient. This past trip we stayed onsite specifically for free dining, so we were a little more "tied down" than usual, as we had to make sure our park days and ADR's coincided. However, this trip was all about trying out the WDW restaurants, so hey, it wasn't an issue. We did several unplanned things, including take a DVC tour (they were giving super fast passes and free ice cream- how could I say no?) which was a lot of fun and really, really makes me want to buy in! On a rest day (planned 5:30 adr at Kona, then to MK for EMH until 3am, WAHOO

), we ended up taking a bus to Epcot, monorail to TTC, ferry to MK, water shuttle to WL (we'd never seen WL before), motor sailboat back to MK, rode the resort monorail, then back to POP (DD was hoping we'd get to take the tram to the parking lot and back... we miss the monorail and trams wehn staying onsite).
Mostly we just took each day as it came, and twice we changed our adr's during the day, so we could do what we wanted (yes, during free dining, and we got our seatings!). I think from now on, I will only plan to the extent of park days and ADR's (which used to be PS for priority seating, but they are one in the same), and just go with the flow! Of course, that's easy to do when you know there will ALWAYS be another visit!!