The kids' schedules are fairly rigid.
Resort second - we have settled in at POFQ after trying others. I suppose this could be first since it is generally not much of a discussion, but in case we change resorts, I want to have a reservation early so I can get the AAA discount. I usually do this more than six months in advance.
Parks next - this can get tricky if you are going early in the month. We try to choose where, in general, we will be on what day. We usually leave some periods open. For example the afternoon of the second to the last day and the morning of the last day are open for our upcoming trip.
Restaurants and tours next - we want to be in the right area for a meal or tour or the travel time eats away at your time in parks. This can get tricky with some restaurants in high demand. If the ADRs are not made early, you may not get a restaurant you want. If you want it bad enough, you may have to change your park schedule.
Attractions - I don't subscribe to a touring plan. Too rigid. I do subscribe to a general plan of what we most want to do, would like to do and don't care for much/ Between advice on these boards and the available apps, it is pretty easy to plan a rough order. There are some that have to be handed early; Toy Story Mania, Soarin', Test Track, Peter Pan, etc. I did use a wait time app to plan my next steps by reviewing wait times at different hours of the day. Still you need to be flexible because of uncertainties.