I found a way to make my tour planning a lot less stressful. I put all of the attractions from each park on an excel sheet. I sat down with the family and we together rated all attractions as one of these:
Must Do - This is why we're going to Disney, no way we're missing it
Want to Do - We're going to do this!
Don't Care - No big deal if we miss it
No Interest - We wouldn't do it even if there was no line
Armed with this information, I immediately remove the "Don't Care" and "No Interest" from the list. We might end up visiting some attractions in the "Don't care" list, but there's no reason to plan for them.
This reduced my touring plan to:
MK: 22 Attractions
Epcot: 11 attractions
DHS: 8 attractions
AK: 7 attractions
With this narrowed down list, picking FP+'s are super easy, and making a general plan to hit them all is no big deal (2 days at MK and 1 at each other park).
Must Do - This is why we're going to Disney, no way we're missing it
Want to Do - We're going to do this!
Don't Care - No big deal if we miss it
No Interest - We wouldn't do it even if there was no line
Armed with this information, I immediately remove the "Don't Care" and "No Interest" from the list. We might end up visiting some attractions in the "Don't care" list, but there's no reason to plan for them.
This reduced my touring plan to:
MK: 22 Attractions
Epcot: 11 attractions
DHS: 8 attractions
AK: 7 attractions
With this narrowed down list, picking FP+'s are super easy, and making a general plan to hit them all is no big deal (2 days at MK and 1 at each other park).

At least I know my priority list when that falls through.
Usually, though, it's not too hard to plan because it's just BF and I, and we're pretty easy-going.
I don't know how you guys who have big families do it!