Mr. Speaker
Adding the in-ceiling speakers. One in the kitchen, one in dining room, two in the wood soffit on the back deck, and two in the cathedral part of the living room.
Keep it tidy
The night before we left for Africa I was at the house til midnight or better running all of the in-wall/ceiling speaker and hdmi wires. The walls would (hopefully) be insulated and drywalled by the time we got back, so it was now or never.