Traditional 18th-19th century tools and methods for leveling frets are a game of eyeball guesswork.

It starts with not measuring: watch the other guys' videos, none measure. They make grand assumptions and blindly plow ahead in the dark.

The result: butchered frets via sanding beam, bulldozed flat crowns and destroyed fret radii that are supposed to match the fretboard radius.

Next they use a freehand file to eyeball and guess at the crowning without any consideration for the fret radius.
Have you ever seen a video by these people that shows addressing the fret radius? No, not one, because they cannot eyeball guesswork the fret radius to be the same for every fret, and so they all ignore the fret radius, or shall we say, lie by omission. They never unveil the nasty truth that when a fret does not match the fretboard radius means that across the length of the fret it is a different height off the fretboard, meaning, yep, you got it, not level.

It is impossible to achieve true level frets with sanding beams and guesswork files.

Next they use a primitive fret rocker to find the really bad uneven frets and cheat them down.

Then comes jerry rigging the setup:
Nut slot depths are based off the tops of the first and second frets, but because these were so sanded and filed by guesswork they are uneven from the low to high E and the middle, hence the nut slots must unavoidably be off spec.

Then they cheat the string action high.

And the final step, the big cover up, they set relief in the neck, more often than not in the extreme.

NOTE: Neck Relief adds an inward bow between the 7th and 8th frets, this shortens the tone scale, hence it degrades the intonation of your guitar. Everyone says it gives space for the oval shape vibration of the strings... this is a lie told so many times that as Hitler said, tell a lie often enough and it becomes the new truth.

With all of that jerry rigging the guitar plays stiff and slow, the tone is off, bends fret out early, sustain dies in the blink of an eye, but yay, they managed for the moment get rid of fret buzz.

In short, paying a shop for fret leveling is all too often a negative experience.

Their Grand Defense: Fret leveling has been done this way for more than a hundred years. Uh huh...
With that archaic logic, sell your car and commute on the freeway in a horse and buggy.

Here in the 21st Century, we have the tool technology to forever change for the better the way frets are leveled so that there is no need to jury rig the setup to compensate for and hide wonky frets.

Precision: All Precision Work starts with Precision Measuring. This requires having precision measuring tools. SixStringers makes that real with our digital gauge adapters and nut slot gauge. Combine with 21st Century Engineered Precision Tools and methods specifically made for the job of leveling, radiusing & crowning frets. FretMaestro.

Don't jerry rig the setup:
TRUE LEVEL is when every fret is the same height off the fretboard, every fret matches the fretboard radius meaning every fret is also level across the width of the fretboard!!!
Only then can the setup be made without jerry rigging.
Only then can you have the neck flat without relief, and with that comes the lowest possible buzz free string action, the softest smoothest fastest play, the cleanest intonation, deepest bends, and sustain for days.
This is how it is supposed to be, this is what every guitar player wants, and there is only one way to achieve it... FretMaestro.