I do a spreadsheet by day. Each day has ADRs and activities with confirmation #s and a rough itinerary including park, transportation, FP+ reservations. I'm probably going to try to coordinate outfits a bit as well but the outfits will be labeled in bags in the suitcase so I don't need it in the spreadsheet. I've left it pretty rough on some days as the kids don't know and won't really know the parks they want to repeat until we are there so I figured we can play around with the last part of the trip later. Behind that I have tabs for the actual stay confirmations (one for USO, one for each of the WDW stays (split stay)), another with a print-out of the
MDE page as it currently stands, one with a copy of our tickets (one subsection for USO and one for WDW), one with air travel info, one with rental car info. The order goes itinerary/spreadsheet, MDE page, stay confirmations, tickets, air, rental. That's all I have right now for the binder. I've also been working on a packing list and a grocery list already and those will likely go in the back as well.