It all depends on what size guitar, acoustics I have seen up to a 20 fret scale for dreadnoughts, electrics 24 or 26, and bass I've seen a 32 fret scale. I went with a 24 fret scale, the hardest part was measuring. Lol I used a digital caliper and just went from fret to fret, double checking with an old 24 fret fingerboard, and after the marking used a fret saw with a laser level and miter box.
After doing it once, I would rather just spend the money on a pre cut fretboard, Carvin makes good ones.
And I wouldn't call myself a luthier, I don't do it for a living. I would love to, but without the skills that come with years and years, I wouldn't be able to keep up.
And yes, if someone was to place a request to me for a custom guitar, I will build them one.