This last week was the 10th anniversary of the fire that effected thousands of people here in Southern California including our family. I was at my mom's and we were trying to troubleshoot something that was going wrong with the AC in the house that was rebuilt after the fire. She got out a large scrapbook that was filled exclusively with pictures of the house during construction. We were able to go through the book and look at what was inside of the walls to help with the issue we were having.
Although we don't look through the book a lot, through the years we've looked at that book several times and we are always grateful the book exists. This weekend my mom said she probably would never have taken so many pictures, but because I live 120 miles away she went to the house every night and took lots and lots of pictures of everything and then emailed them to me so I'd have something to talk to the contractor about the next day (and there was always lots to talk about).
This made me think that it would be a great tip to tell survivors to take pictures of everything, especially before insulation and drywall is installed so you can see where those pipes and wires are once they're covered up. It will be an invaluable resource later!