How do you clean your guitar?

first of all, the best thing is to keep them in a case when they're not in use. I give mine a wipe down with a duster when I put them away, and the frets and fretboards get a good clean whenever I change the strings. even if I am just changing one, I clean the area under that string. a good way of cleaning right up to the edge of the frets is to fold a cloth around an old bank card or similar, and that gets all the old finger grease out right up to the edge. you can also get something called fast fret, which comes in a sort of stick. you use that to wipe down your strings and fretboard, and it helps keep it all clean and in good condition. hope this helps.