My usual advice is to focus on wall warts and cable routing. Keep any power supplies (i.e. wall warts) for your network away from power you’ve cleaned with a conditioner and keep IC’s and power cables away from Ethernet cables. Of course, using separate AC circuits is ideal for network routers, laptop power supplies, etc.
Otherwise, beware of network sourced surges. One low voltage lightning surge through your cable modem and Ethernet infrastructure can take out most of your entertainment center. I wrote about this at some length here.