I've used the standard fare guitar hooks before and had three of them in our brownstone, but I knew I wanted to have at least six hangers in our music room. I could have just bought three or four more hooks, but they always seemed like eyesores and I wanted the guitars to seem like they were sort of floating on the wall.
I picked up six unfinished wooden plaques from a craft store for about 50 cents each and six of these gray vinyl-coated screw-in utility hooks from Home Depot at less than a dollar each. I measure and marked the center of each plaque, drilled a pilot hole and screwed in the utility hooks by hand.
I laid out the guitars on the ground and figured out the best horizontal spacing for our new guitar hooks, based on the width of the instruments.
Then I hung all the hooks on the wall with drywall screws (either two or four screws each, depending on the weight of the guitar) right through the plaque and into the wall, all at the same height.
Then we painted the plaques and the screws with left over wall paint (Farrow & Ball's Green Blue). I decided to leave the hooks gray because the color was not all that different from the wall and I didn't want any of the paint to rub off on the instruments (some of them are really heavy). This was a last-minute project before the Domino shoot - if I had had more time I might have tried spray the hooks with my critter sprayer or something so they'd all be a uniform color. But we were up against a time crunch and the gray is hardly noticeable in person.
They are super secure on the wall - we've had no problems with these, unlike the "real" guitar hooks we bought at a music store, which would bust out of the wall all the time, or the prongs would flip over. The vinyl dip gives a great padded grip on the guitar necks, and somehow work on even the skinny necks of the ukelele and the banjo. And of course I love that these hooks pretty much disappear on the wall. DIY wins again!
PS My sweet mom gave me this beautiful antique Russian silver filigree bowl a few years ago and we use it for holding guitar picks. :)