Lots of different advice above. Thing is, the "best advice" is really going to depend on your particular environment, your devices, and what you are trying to accomplish.
You'll want the different AP's on different channels. Which channels, and whether 20/40 or 40, and whether fixed channel or auto.... Is really going to depend on your environment. I much prefer fixed channels, but as TeMpL says, if you have people around you and they are changing channels from day-to-day -- then you may have to join the party and go Auto to keep your sanity.
I prefer using the same SSID/Password for all the 2.4g access points, and another SSID/Password for all the 5g access points. I don't use the same SSID for 2.4g and 5g, because I want the 5g-capable devices to connect to a 5g signal, and always stay with a 5g signal. But I do want them to switch between the AP's (on the same band) as they move around the house, so having the same SSID/Password (for the same band) is the simplest way to facilitate that.
I also find that with the devices *I* own (this varies by manufacturer and the drivers they supply), they switch off just fine between two AP's that use the same SSID/password. No need for having multiple SSID's and setting up multiple profiles on each device.
So my advice is... Look at all the advice from everyone above, decide what your goals are, then test out some different methods in your particular environment, with your particular equipment -- because that's really the only way you will be able to determine what works best for your combination of AP's, devices, and signal environment.