After a fret level, your guitar will benefit from a setup. Fret height will have changed and the impact on nut slot depth, action and intonation should be assessed and addressed.
A fret level isn’t always possible or desired. It may be that the fret wear is too deep to leave enough height to level or it may be that a player doesn’t want the frets lowered due to her playing preferences.
Well then, we’re probably looking at a refret.
To refret, I have to remove the existing frets and install new ones. The new frets are cut to length and have their ends bevelled and rounded. Then, I go through all of the fret level steps listed above.
There are other reasons than wear that might make us consider a refret. Humps and S-shaped necks might push us to refret so that we can do some levelling on the wood of the fingerboard itself. Relief issues might prompt corrective refretting (where we use different shaped tangs to force the neck into a straighter position). And, some repairs can mean we have to refret afterwards.
Most of the time, though, we’re refretting to address well worn frets—the result of putting the guitar to good use.
If you’re planning some fret work—especially a refret—get someone you can trust. Ask around and get some recommendations as a poorly executed refret can do nasty things to a neck. Find a repair person you feel confident with and you should end up with a beautifully playing guitar with some shiny, shiny frets.