Hi, fellow experts ! I am trying to make my own Dupont Wires and I have some questions :
Thanks for everything !
Buy a kit. You need a ratcheting crimper. gauge depends on specific pin you use. 20-22 is typical. Bigger (20) is usually better mechanically.
Single pins have little retention. I 3D print shrouds that gang the pins. Makes them easier to insert, holds better, and gives a place to label & mark pin 1. The kits have grouped shells.
Its really not cost effective to crimp individual wires when you can buy premades. I buy M-F 30cm (12") sets. You can cut either end, to get either pins or sockets coming off screw terminals, or use them as-is for extending stubs.
A 40 wire M-F ribbon is about $8 and contains 80 stripped, pinned, crimped, and inserted pins. Thus on stripped/pinned/crimped/inserted terminal is $0.10 including materials!
At minimum wage $8 is about 1/2 hour of labor. How many good crimps can you make in 30 minutes? Certainly many less than 80. Ergo, buy rather than build is more cost effective.
Don't worry about isolation everything will insulate low voltage +5.
Yes, I want to buy a kit. But it tels me to tell the isolation and the AWG
For ex I can take AWG20 with silicon isolation
But I don't know what's the best AWG and isolation
On my local stores 40 Dupont wires are 5-6€
And if I want to buy every tipe is almost 20€
In my experience, one must check every jumper from the cheap bundles. I use a 12V DC source and an old back-up-lamp: simple.
Thanks !
20W lamp - 2 Amps approximately. 
- What type of isolation should I use : PVC or Silicon
PVC is fine. Silicone is nicer feeling, but more expensive and thicker. The usual advantage of Silicone is high-temp resistance, which is unnecessary if you're crimping.
- What AWG number should I use ? 20, 22, 24, 30, etc?
22 or 24 should be fine. Should be stranded, for crimping. More strands usually means better flexibility and durability, and more $$.
- What tool is the best for that AWG number
The really expensive one! 
(sorry - no actual experience on optimizing performance/cost. I have a cheap non-ratcheting crimp tool that seems to work OK, but it's a pain to use and I don't trust it very much. It's probably not matched to the connectors I've tried to use (and it should be.))
Thanks!
Your experience with a cheap crimp tool matches mine. Mostly I get good crimps but sometimes not and just when I think that I have got the technique right I get a run of failures
This one is good ?
It's ok the AWG number ?
Dupont jumpers usually have stranded wire, not solid.
If it is good the AWG, I strand them myself
Stranded means multi-conductor.
What do you mean by that ?
I buy the conectors and the special tool and whit the wire I make my own Dupont Wires
