Following is a list of 12 essential tools and accessories that will help you keep your fingers and your guitar in tip-top shape and in good working order and provide you with the hardware to create a variety of music. All the following items are fairly inexpensive; they can fit easily in a resealable plastic bag and be stored inside your guitar case.
Electronic tuner/metronome
Extra strings
String winder
Cleaning/polishing cloth
Pencil and paper
Digital recorder
Mini toolkit: Screwdrivers, wire cutters, pliers, allen wrenches
Nail file/emery board
Capo
Picks
Slide
Strap