Is there anything worse than a guitar with tuning stability issues? That’s a quite annoying problem that is often seen as an instrinsic (and unwanted) characteristic of the instrument, a part of its nature: “it’s a beautiful sounding guitar but it doesn’t stay in tune”.
Typically the issue is addressed with an extra investment in terms of upgrades (such as locking tuners or a new bridge), a modification of the instrument (such as blocking the tremolo bridge) or of our habits (such as changing the gauge or the brand of strings). Other common tries are using lube in the nut slots, adding an extra spring to the trem claw and many others.
All the above mentioned are meant to bring, each to a different extent, some extra stability to the tuning but are not the solution.
As often happens, the solution is much easier and more at hand.
Here it is, in three simple steps.
1) Learn how to string properly.
You don’t really need any lock or tie, even less locking tuners (although those come in handy for a super-quick restring).
Keep it simple, keep it clean. One winding above the string cut and one or two below is all you need.
2) Stretch your strings.
This is a critical step which really you can’t skip. Once you have installed a fresh set of strings and you have them in tune, put your guitar on a soft cloth on a table and stretch one string at a time.
The way I do it is based on two movements on each string:
(1) From the above push down on the string with your thumb and pull it up with the other 4 fingers, all along the string (while holding the string in place at the nut with the other hand):
(2) From the outside to the inside, again pushing with the thumb and pulling with the other fingers:
Each movement has to go long the whole string, from the nut to the bridge. Try to alternate the two movements and remember not to stress too much the high E string or you will risk to snap it. At the end of each stretch, check if string is in tune: at first the string will come out few semitones flatter but, stretch after stretch, will go less and less flat.
You know you’re done with that string when it stayed in tune after a stretch.
Don’t forget the section after the nut: here the movement is just a gentle pushing and once is more than enough.
3) Have the nut slots cut and polished.
This is another must, even more in presence of a floating bridge. If you ear some strange “pings” coming from the nut while bending or tuning the strings (or when using the floating bridge), it means that it’s time to have the nut properly worked as the slots are trapping the strings (i.e. the strings don’t return to the zero point after the mentioned actions, so , for example, after a bending the string goes sharp). That “ping” is the noise of the string fighting the surfaces of the slot which is too narrow or too irregular. No lube will be helpful at this stage, not before having the nut properly cut and polished (here the article on the nut slots).
Extra: if your guitar comes with a trem bridge or a Floyd Rose, you may also need a proper setup for this system, as it’s critical for this to have the correct balancement between strings tension and springs tenson.