Years ago there was just two ways to wire multi switches to work one set of lights, this
was what we would normally find.
However things have moved on, electronic switches can be linked still using master/slave idea using just 2 wires, or even no wires. Even pre the electronic switch, we got pneumatic time switches for stairs.
However in the main the intermediate switch will do all. The two way switch either on/off or two way, and the on/off only on/off. So when changing the style of the switch, look for intermediate switches, as in the main you can get the other two in same style, but some lines don't have the option of an intermediate switch in their series.
I found I could get two gang intermediate, but not three gang, so I had to wire so intermediate was only a two gang switch.
Today many smart switches don't have a hard wired option for extra switches, I have started to use TP-link (Tapo) smart switches, which don't even have a two way option, but can use a button to change state, or phone, although not convenient as I don't walk around with phone glued to ear, but also can use voice control, very handy with hands carrying coffee and want the light on.
So stop an consider future needs, even if you don't get the smart switch, bulb, relay now, when you do start to change, want it to look similar to existing. I find this
switch is easier to turn on/off with my elbow to this
switch, large plate which does not need bare skin better than small button which needs skin to touch it to work. Also my house some switches have a neutral, but most don't, so for switches to match, needs to work without neutral. And having to select bulbs which don't stay on dim, and don't shimmer when on is also a pain, which is why I use Tapo, however it does have minus points too, it needs a battery, which will need changing around every two years.
But before you rush in, consider what you will want in the future. My landing light switches are never used, always use voice commands, but still have the switches should I want them.
