When I'm gigging, I come home, and wipe the guitar down with a damp rag, including strings, and buff dry. Then I use the Dunlop 65 String cleaner to coat, clean and preserve the strings.
Strings last me about 12-15 hours of gig time, and about 20 hours of sofa time. I hit hard, so my issue is fret wear on the strings.
Fingerboards are cleaned with each string change and oiled once or twice a year. I polish as needed, and use a carnauba wax on my NCL-finished Gibsons.
Clean hands...of course!
My dad was a precision machinist, worked in a defense plant during WWII, and did a lot of mechanic work. He'd farmed, and loved working in his garden. One of the axioms he passed on to me was keeping his tools maintained: clean, dry and lubricated. It is an ethic that has served me well over the years.
I take meticulous care of my guitars. I have sixty guitars, and that's a substantial amount of money. Why would I NOT take care of my investment?
Bill