Start by wrapping a length of wire into a circle about 3-5 inches in diameter, based on however wide your guitar's head/tuners are. We'll be wrapping this around them.
Cut the wire!!! Wire cutters!!!
Braid the wire together. If this is aesthetically unpleasing to you, you can also crimp the cable. If strength is a concern, you can use duct tape to wrap around the braid. Important part: circle!
Place the circle around the top or lower tuners. You can play around with this part to show more or less of the cable.
Ready to hang!
I use 50 lb. hooks, but this can be just about anything you want that can have crap hung on it.
Boom. We're done! This is a ukulele, but you get the idea.