First, plan you park days so when you are ready to book your restaurants, you know you do nto need to either change your plans, or run hitter and yon just to eat. THink about how you will want to tour and how you like to eat, and I always look at the previous year's hours and show times. Of course that is not to say the times guides are written in stone, but you will have an idea.
After I make a rough touring plan, and I mean a really loose outline of park days and any special event I need to work around, I look at my dining choices, and the times I think my family will want to eat. I put them in order of difficulty and book in that order.
IMO, restaurants like Jiko or Tiffins do not book up as quickly as California Grill at Fireworks times, so I woudl book my CG first.
PPO restaurants that offer any kind of advantage book quickly, so if you want BOG breakfast, or Garden Grill or AKershus before the park opening time, book them first.
For some reason, SCi Fi in DHS is popular so if you want that one or 50's you woudl place them in the early booking order, however if you wanted Brown Derby, I would not hae that one up front.
I also do not lose sleep over any restaurnt that I could not book. SOme of our best meals have been our 2nd choice.
