2) When crawling around in your attic, don't decide to stand up and tug on a wire as hard as you can so when it doesn't give, you fall through the ceiling of your house ass first.
3) When you do fall through the ceiling of your house, make sure your extremely calm brother is there with you so he can walk into the room where you and your fiance are repeatedly uttering, "Oh my god, oh my god", look at the damage, shrug, and say, "It's just drywall."
4) Being friends with a local contractor is really really handy.
5) Spray insulation does not feel great in your lungs, wear a mask.
6) Getting through a day where one of you causes hundreds of dollars of damage to your home and being able to wake up the next day, laugh about i,t and support each other is the sign of a relationship that is going to work.
7) If you have a project that requires you to crawl around in your attic for hours...maybe you should just HIRE someone.