As said, power sockets everywhere you need – I’d love to rewire just to do away with all the power strips. Likewise network sockets where there’s fixed equipment (so near TV, home office desk, Sonos speakers if you use them, etc) and to wireless access points. You can buy APs like Ubiquiti Unifi pretty cheaply now, they’re very unobtrusive (but could still hide in a cupboard if you wanted), straightforwad to set up, powered over ethernet, and you just put in enough of them to get good signal everywhere you want it. If you’ll have an alarm system, better to put wires in than have to do wireless later.
Think about things that can moved to better places – eg relocate master socket so your broadband router can be in a cupboard rather than by the front door.