Hi! What are these clicks when tuning the guitar? Specially the thinnest strings. It clicks and the note immediately goes high when it gets close to the ideal spot. It happens when lowering down as well but since we are supposedly to tuning going up, it makes the note sharper, passing the ideal spot. I have to tune the strings slowly trying to avoid this.
Best regards.
Check to see if the strings have cut a groove in the nut and are sticking then releasing when you turn the machine head. You may need a new nut or the nut slots re cut.
Looks like a luthier job 
What you are hearing is “stick and slip”–sort of like when an earthquake resolves the tension between one side of the San Andreas fault and the other. In your case, it is the result of friction in the nut preventing the tension of the string from equalizing as you tune. The string stays stuck in the nut [the “stick”], until the difference in the tension from one side to the other overpowers the force of the friction, and it makes a sudden equalizing [the “slip”/earthquake].
The 1cent way to make the symptoms go away is to put a tiny bit of lubricant in the slot the string is running through. Chapstick I’ve seen suggested.
My luthier advised to avoid using oil as it could make future gluing, should it be necessary, in the area problematic.
I use basic graphite for my nut lub. I getnit at the hardware store. It worrks really good in sticky key locks and is super cheap.
Is this a normal behavior? We actually need to lubricate even on a “perfectly” setup guitar (not saying my guitar got a perfect setup)? Does the nut material makes any difference?
To lube mine I use a pencil - graphite is a pretty good lubricant.
I don’t think I’ve ever come across the clicking sound you describe, either in my guitars and basses, or any I’ve tuned in a shop. I’ll bow to the greater knowledge of others though as to whether it’s normal or not.
Yes, that’s the easiest option. Get yourself a 4B pencil.
I don’t know whether you’d say it’s “normal,” but it’s not uncommon.
is correct, it’s not uncommon, Electric string can click for different reasons.
If the nut isn’t lubricated, or if the nut is slightly mishaped a little and a winding clicks over an edge. I’ve even heard nylon strings on on non mechanical tuners do the same but I think thats the sticking of wood on wood friction.
you certainly do not need a luthier, next time you strip the guitar make sure to give a it all a good clean and lube the nut , make sure the ball ends are properly seated too, and use good quality strings.
Nothing to worry about, just a nuisance and if it happers to go sharp just try again, no big deal really.
I like bone nuts, easy and cheap, I can get the blanks and cut my own really easy. There are a lot of other cool materials also. TUSQ a man made ivory which is really good. I would swap out anything plastic personally especial plastic. The plastics are not as good.
I did this a while ago (with another guitar if I remember correctly). I wonder if graphite is bad for the strings (damaging them)?
By “blanks” you mean untouched raw material? Also, does the word “TUSQ” means something?
I forgot to mention that I play (or try to play ) acoustic guitar.
Could you remake this phrase? English not my native language 
What are mechanical tuners? I thought all tuners are mechanical? 
Also, what “sticking wood on wood” means?
Now this is rabbit hole, different people says different things when it comes to guitar and strings cleaning 
How can I do that? I tried to place them the way Justin teaches (the little kink advice at 8:19). I changed the strings yesterday and I think I put them on correctly, at least almost all of them. There’s no way to know if the balls are correctly positioned (for me at least), but I felt the strings when I pulled them on the bridge. I don’t think they’re under the pegs. They moved up when pulling.
I use Ernie Ball strings. Ernie Ball is the way to go
No matter, can still happen, steel strings?
Always 
Probably fine, it’s nothing to worry about, like I said just a nuisance lol.
I know right
Do you think something like this it’s worth it?
To be honest no, I could do the same job with car grease or as already said, graphite lol. But, nothing is stopping you and it’s a good idea to use something to lube nuts n saddles
The saddle also needs lubrication?
no. graphite is pretty inert.
TUSQ is the name of a specific product made by Graph Tech.
TUSQ Nuts | Graph Tech Guitar Labs
you could use the term “geared” as well to refer to “mechanical” tuners. Some tuners (particularly like you might find on a ukulele) aren’t geared. they just use friction to hold. Note they’re also called “friction pegs”.
Waverly Ukulele Friction Pegs - StewMac
I think this is what you might refer to when you say “non mechanical” tuners. But according to a strict definition of the word “machine” I suppose all tuners are at least simple machines. Which would be why they are commonly referred to as “machine heads” or “tuning machines”. The language, even for native English-speakers, on this is muddy, if you will.
