If you’ve ever messed around with your Wi-Fi router’s settings, you’ve probably seen the word “channel.” Most routers have the channel set to Auto.
If you’re using the 5GHz band, and your walls aren’t paper-thin, then attenuation and the general lack of 5GHz devices should mean there’s little interference in your apartment — possibly even allowing you to use the fatter 40, 80, and 160MHz channels if you feel like it.
Eventually, as everyone upgrades to newer hardware and moves towards 5GHz, picking the right channel will mostly become a thing of the past.
Bear in mind that interior walls do a pretty good job of attenuating (weakening) a signal.
If there’s a brick wall between you and a neighbor, you could probably both use channel 1 without interfering with each other.
Guidelines are just that, something to drive you in a direction and help during certain scenarios, but not an all encompassing set of instructions on how to perform a penetration test. Selecting the tools required during a penetration test depends on several factors such as the type and the depth of the engagement.