A bit of both depending on how you like to do things. Personally, we go with the flow. We sometimes try to have a plan of what to do first, but more often than not that changes when you get there.
IMO, people get way too hung up in dining at Disney on the whole, panicking to reserve months in advance and planning each meal. We ate in the village each night, only pre-booking Cafe Mickey for the characters, and ate all where we wanted. The only place we wanted to eat for dinner in the park was in Agrabah and that was shut when we turned up just before 6pm so we went back to the village and got into La Grange when it opened. Although as a caveat we usually go out of season in Jan/Feb so June may be a different kettle of fish. But even so, there's still Vapiano's and Five Guys as well as Annette's, Rainforest and Planet Hollywoods which can be done without a booking (although not a good idea after the fireworks show, we found 5/6pm a reasonable time).
Rides wise, we wanted to make sure we got on everything we could, but you can't really plan that much until you know what the wait times are like at that time. Once you're there, you can gauge things a lot better and know when to go. A good plan to start with would be to get a Fastpass for a busy ride you want like Rataouille or Big Thunder Mountain each day as soon as it opens and fit everything in around that and the show/parade times. Just try and work through all the rides you want to do, and use the App to see what the queues are like, or ED92 on Twitter if you're into character meets. You can do a lot with a plan, but equally you can miss a walk-on, short queue or surprise meet if you're sticking rigidly to a schedule.
We used our last day as a greatest hits day as it was a half day before the train home, but made sure to queue up for TOT when the studios opened as the queue for that was long.
If you like planning, go for it as DLP is a place where you can plan everything to the nth degree if you wish, but don't be afraid of screwing it all up when you get there!
