What you really need to do, is first decide where you want to be on what day. Then every thing else falls into place. Before I didn anything else, I sat down and decided what parks to do (or not do) on what day. It also helped that I looked up last years park hours and fireworks schedule so I had a rough idea of park hours and show times. Once I determined where we'd be, it made picking where to eat and what non-park activites to do much easier. Here is my December itinerary as an example:
Day 1: Fly to Orlando, transfer to Poly, check in, dinner at 'Ohana's and desert durring MK fireworks at California Grill.
Day 2: MK all day. Pre-park open PS at Crystal palace, lunch is open, dinner at Tony's.
Day 3: Epcot all day. Room service for breakfast, lunch is open, dinner at Mexico.
Day 4: Non park day, sleep in. 10 AM PS for Chef Mickey's, lunch is open (we may not eat if we stuff ourselves at Mickey's) horse back rideing at 2 PM, 7:15 PM Hoop De Doo.
Day 5: MGM all day. Room service for breakfast, Sci-Fi Dinner for lunch, Fantasmic Dinner package at Brown Derby.
Day 6: Non-park day. Room service for breakfast, surprise Richard Petty experiance for BF in the morning, afternoon free, evening at DTD, dinner most likely at Fulton's (haven't decided yet).
Day 7: AK. Room service for breakfast, lunch open. Leave AK at 2 or earlier, break, then possible PS at CRT, then
MVMCP.
Day 8: MK/Epcot. MK keys tour, then more park time at MK or break, then Epcot for dinner (haven't picked where yet, maybe Moroco?) and Illuminations.
Day 9, check-out. Breakfast will be room service or Kona's, transfer to airport, fly home
As you can see, since we know what park we will be at on which day, our location narrowed down our options of what restaurants we could choose from. I then picked the time I feel we'll most likey be hungry by (that's a bit of a gamble, but nothing else for it). I also try not to make more than 2 PS's for one day, otherwise you become a slave to eating and restaurant reservations. Also, we've spread out our non-park days to give us a break from the parks, so we don't get worn out. It's on the non-park days that we do some of the activities, like pool time and horseback rideing. The tour I left for the last day, only because this is BF's first visit to MK, and his first day there I want to do what we feel like doing and explore the park on our own, not be bogged down by a tour. Then later he can learn all about the behind the scenes stuff.
We only have 3 non-park PS's that aren't at our own hotel, CA Gril, Chef Mickey's and Hoop De Doo, this minimizes trying to get from our resort to another, which is THE most complicated type of transportation needed if you are relying on Disney transport. It's a personal choice, but I hate the hassle of resort hopping, especially just for a meal. For these three particular meals, transport from the Poly is simple, as CR is on the monrail line and there's a boat from Poly to Ft. W. But, if there is a place at a resort you're just dieing to try, just plan extra time for transport. I'd recomend keeping resort PS's at a minimum if possible though, unless you'll have a car you can take instead of the busses. Otherwise you'll be spending a lot of time on busses, and who wants that?