Sort of following on from previous and recent questions around
crimping (and my personal / general preference to both manually crimp
(if available) and solder) here, I just checked out another of Big
Clives Youtube videos on crimping pliers for use on the small
connectors you typically find in electronics gear and specifically the
2.54mm 'DuPont' connectors we often use with microcontrollers like the
Arduino / ESP32, various sensors and PC mobo headers etc.

One of my latest projects, a 'Charge Multiplexor' allows me to spread
a single good / intelligent (fairly expensive) 12V maintenance charger
over up to 8 LA batteries using Home Assistant home automation system.

An ESP32 WiFi microcontroller driving 8 relays and a INA219 current
sensor monitoring the charge current and voltage (mostly for logging)
that atm I've tacked together in a 3D printed box using wires soldered
directly to the boards and / or screw terminals where supplied.

Now in theory, once built it shouldn't need to be touched again (you
can even change the firmware over WiFi) but I was thinking of what I
would have to do, should I need / want to replace any of the modules
in the future?

So I was going to replace the ESP32 direct soldered wires with the 2 x
19 pin male headers they generally supply with these things and use 2
x 19 way housings (20 ways cut down) with female crimp connectors and
with paint markings on the plug body, ensuring the use of the correct
connector the right way round. Whilst no more than 12 of the 38 pins
on the ESP32 are used for this project, by using 'full length'
connector shells, even if only partially populate means there is less
chance of mis-locating the plug / socket combo. Also, if I use a
ribbon cable for the screw terminal connection to the relay board, it
will also remove any question marks re wire-to-terminal association
when I forgot what I did in the future (or next week even), wire one
goes to terminal one, two to two etc. ;-(

I would then make this my default 'build style' for future projects.

So, watching the Big Clive video:

https://youtu.be/DXLmuDbcLBM?t=1184

He seems to recommend the IWS-2820 crimping pliers, even though he
makes a bit of a pigs ear out of using them himself on the demo g,
so I wondered if anyone else here has crimped this sort of size /
style connector and if they have any thoughts recommendations on the
pliers please? I normally crimp them manually with my Leatherman
pliers (that doesn't actually do the 'crimping' it the way they should
but just folds each ear over in turn) then solder, then crimp the
strain relief in the same way.

Easy to do in the male as any surplus solder can't really do any harm,
not so easy on the female as you can fill the socket. You also have to
be fast to minimise any insulation runback.

Cheers, T i m