Yeah sure. I will start with saying It is not necessary to do what I do. just my way of making it easier to trouble shoot and install.
I use 2.54 JST-XH connectors. simply because I had them and they fit. 2.54mm is the proper pin spacing for use with the typical board. they are readily available at tayda, mouser, digikey, amazon and several RC hobby stores. I am into RC Aircraft. thus the reason I had them hanging around. As well as I use the same modeling techniques I use on planes, on pedals. not the best way, it is just what I am doing.
I buy the connectors with wire already on them, and the sockets plain. the socket I I use a 4 pin on the board where the switch solders to. on the switch I buy the break out boards from pedalpcb and attach a wiring harness I make from the prewired connector and a piece of header pin. this way, no wire is soldered directly to a board. durability is higher that way.
the power connection from the I/O power board to the main board is done in the same way. the I use a two pin 90° socket on the I/O power board. I have switched to 2mm spacing on these as it leaves the perfect amount of room for the "in" and "out" wires that go from the switch breakout board to the I/O board. the connector side is solder again to headers pins and onto the main board.
Here you can see my dirty cutting mat...lol
Here you can see the I/O power-switch harness that is created when I do this. No wires are soldered directly to any board. they all are soldered to header pins. some right angled like the "in and out" wires as well as the power connector on the main board. for my and my method, the one red on the switch board is the "in". you can see on this harness I have both 2.0mm and a 2.54mm socket soldered on the I/O power board. it is only because I use this harness for quick testing. as soon as I am done soldering up a new board, I slap it on that harness and plug it in to test.
I plan on getting a pedalpcb auditorium test platform soon and utilizing it with the same connector method.
Notice that I am using a different power jack than was designed for the I/O power board to use. It is my personal preference to have it threaded to mount to the enclosure. Also I am probably the only one using those jacks and boards...lol. I actually don't really like them. they are just compact and necessary for this I/O power board.
Most people here do not use any of this stuff. I like modular designs and I am always looking to improve my method. no soldering is done in the enclosure. nothing is permanent. everything is easily removable and serviceable. That is how I build RC planes. Most RC builders do. That is also important at my job as well. everything is connector-ized on control board. that I work on.
Again. not necessary. actually some people might tell you they do not like how it looks. I Agree. It is not as nice looking as straight wire connection.