The safest of all is the more simple : SOLDERING SOL-DE-RING.
Do it one time and never touch it again. It work flawlessly and awesome to your console safety.
Paperclip can damage some pins after an occasional use and let's not talk about screwdriver, you can damage very badly the pins very easily. JiG contact aren't that good and you need a precise printed JiG. A lot of them dosen't take his right place (souce : eBay).
Don't bother my friend, just buy a solder kit from Amazon for like 10 bucks.
I disagree with that. Soldering, if you're not experienced with it, is risky business, especially SMD soldering. I would not recommend to someone to just buy a cheap soldering iron and attempt to modify small electronics. Practice on something that's already broken or something it doesn't matter if you break. And then once you feel confident in your ability to solder small (SMD) components without breaking anything, then you can consider hardmodding.
Also, by physically modding the JoyCon you're voiding its warranty so if something goes wrong now or in the future you have to fork out the cash for a new one.
Jigs are cheap, easily available (now that multiple people have started selling premade ones), and at least with the wire-based jig, there is nearly zero chance of breaking the pins, the jig only fits in the right way and the wires are soft enough that even if somehow it was inserted wrong or the wires are out of place it's not going to damage the pins. The only way you could damage anything with a jig like that is if you managed to bridge the power rail to something else, but as the jigs usually use pin 1 and 10, and the power rail is on pin 4, that's very unlikely to happen. It's far more likely to happen by jamming paperclips, needles, tin foil etc. in there (plus the much higher chance of physically damaging the pins), so it should be obvious to anyone that that's a bad idea.
But it can be slightly less reliable, I'll give you that. Still not a big problem, just adjust the wire when needed to keep it working. Better that than a broken JoyCon.
Also, according to this:
https://reswitched.tech/hardware/joycon
The JoyCon will not function when pin 10 is low (such as when it's bridged to ground with a hardmod), I haven't heard anyone mention this yet, but that essentially means that you are going to be sacrificing a JoyCon if you do a hardmod and that's another thing you'll have to carry around with you whenever you take the Switch with you.
Is it really bad to use tinfoil now or not? I used it now for 2 days. Is there any Report that a Switch got broken with it?
Tin foil is fairly soft, you are probably not going to physically damage the pins unless you jam a ball of it down there hard. What you have to worry about is accidentally bridging something that shouldn't be bridged, such as pin 4 (5V) to basically any other pin, which could damage whatever in the Switch is handling power delivery to the JoyCons, could damage whatever the other pins you bridged go to, and could even damage the battery. The damage could happen immediately or over time if you accidentally bridge pin 4 multiple times on separate occasions.
Also, you also have to be careful that a piece of tin foil doesn't break off and get stuck in there without you noticing, otherwise once you connect the JoyCon and the piece is moved around it could bridge multiple pins.
I really recommend you get a jig from the person I mentioned above, you won't have access to the trading section yet since you have less than 100 posts but you can PM him directly once you have 10 posts (
https://gbatemp.net/members/subcon959.149494/), it's dirt cheap. Or get one off eBay or whatever, it doesn't really matter other than it costing more. I wouldn't get one of the paperclip based jigs, cause they seem like they wouid be far more likely to damage the pins over time, as they are much harder than wires. But that might just be my paranoia.