It is a good habit to wipe down your guitar or bass with a soft cloth after each playing session is a great way to keep finger gunk and oils from building up over time. You can also set a time every week for a quick wipedown. That’s a great way of keeping your fretboard clean. At the least, give the fingerboard a good wipe down every time you change strings. A clean fingerboard feels and looks better and will extend the life of your strings.
But a more long-term concern is your fretboard drying out, cracking, and wearing. For that, many manufacturers recommend every six months you should clean your fretboard with a specialty wood oil. The better oils are natural, such as Dunlop’s Lemon Oil orFender Custom Shops Fingerboard Remedy the . You don’t need to apply much — you can put the oil on a cloth (not too much, just a big), and then use the damp cloth to wipe your fretboard. By doing this — a quick, dry wipe for fingerprints and oils, and then a deep clean every six months to moisturize — your fretboard should be good to go for many years to come.