How have I been keeping track of everything for our trip? I created a binder. The binder starts with our itinerary on the first page, and behind that page is our travel insurance policy.
I debated organizing it in date order but ultimately I decided to organize by category. I have five different categories: Flights, Apartments, Hotels, Cars, and Activities. As soon as I make a reservation I print it out and stick it in the binder. This has worked great at keeping me organized. When our flights to and from the South Pacific were cancelled I could easily grab our original flight info when I was speaking with a customer service agent. If something changes I print out the new item and keep the original behind it.
As you can see, right now I am using clear plastic sheets for everything. This lets me change things if needed. Right before our trip I plan to take everything out of the sleeves, make copies, and then get everything bound at a copy store. I plan to keep a copy at home for the memories, and obviously bring one on our trip. However after we do an activity or take a flight I plan to rip that part out of the notebook. By the end of the trip I should have nothing.
The binder also helps me with my excitement for the trip. There is just something fun about printing something and filing it in the binder.