I just received my new guitar, and want to make sure it is properly looked after so it lasts. I hear people saying I should use a towel to wipe the fretboard after every use to increase the lifespan of the strings, is this good and how often should I clean that towel. Also when I play where my arm is rested I notice alot of dead skin cells stick to the body, I don't know what to clean it with (been using nails to scratch it off on my old guitar) and how to stop it, do I put something between my arm and the guitar or just always wear long sleeved shirts to play.
Metal, Prog, Jazz

Ibanez SZ320
Jackson Misha HT7

Ironheart IRT Studio 15w Head
Ironheart 2x12 Cab
Use a polishing cloth, Dunlop Formula 65, and elbow grease to get up the arm cheese on the body of the guitar. Use a microfiber cloth to wipe the strings down and keep cheese off your pickups and other metals. Wash the microfiber cloth maybe once every few months. Also wash your hands before you play.
Wiping your guitar down after use is a good idea. Wiping gunk off strings only helps a little in terms of life but does make them far more pleasant to play.