1. Make sure you are using cat6 cables everywhere. Cat5e has a speed of 100 mbps max and cat6 supports upto 1 gbps.
2. Have enough data points throughout the house ... especially where you plan to keep .... modem/router, TV, Playstation / Xbox, home surveillance, study desk, landline.
3. Get Internet connected at lockup stage so you have it at handover.
4. Using the Internet, test all ports at handover. I missed this. I think one of my ports doesn't work.
5. Have a NBN box in the garage with 2 extra power plugs.
6. Have all the data points in the house connected back to the garage/ ur preferred place like a hub.
7. Have two data points at the place where you are planning the router/modem tracing back to the garage or your hub.
This is so that you can switch it around.