A question on a Facebook group a while back asking about modular connectors to keep things simple. While the following is perhaps not simple it is modular and works for me. There are many reasons to do it another way etc, but hey it's my layout .

I wanted to be able to run dropper wires from the tracks to some form of plugin system under the board in an attempt to reduce the requirement to use a soldering iron above my head as my layout isn't easily separated into it's constituent parts and raised on it's edge.  This has expanded into running three wire extension cables for servo's back to PCA9685 servo controller boards and even the I2C, VCC and GND loom from an Arduino to these PCA9685 cards.

My solution was to buy in a load of 'dupot' connector pins and sockets along with 1pin, 2pin and 3pin cases, and  a cheap crimp tool all off ebay. This allows me to make up any type of wiring loom that has connectors at each end so I can plug and play once the wires are below the baseboard.

To start I create a 'distribution board' and use a number of 2 pins cut from a run of single PCB header pins and solder these to stripboard in groups of 4 or 5 with a 2pin screw terminal at each end - see pic below with the blue screw terminals on stripboard for example.  This gets screwed to the underside of my baseboard at various locations.  Heavy duty zip wire (white and white/black) is run between then as a "mains bus."

I then manufacture dropper wires with a dupont sockets on the end in a double pin case:

These then plug onto the distribution board:

The servo extension wires use both plugs and sockets made up from dupont connectors in 3pin casings:

This enables me to have a balance between servo controller boards in locations close to servos and not to have many long runs of servo control cables.

A note on dupont crimping. It takes a while to get into the hang of it. The cheaper tools don't really produce a great crimp without a little fettling after the initial crimp. I've found the insulation part of the crimp may need a gentle squeeze with a pair of pliers and perhaps a general straightening out of the metal socket/pin.  What I have found is that the insertion of the socket/pin into the housing should be very easy with no resistance and there should be a little click as the socket/pin reaches the correct location within the housing.