Paint the plaque 2 contrasting shades of paint. Don't go too crazy. It's for the rock gods, not a clown.
Write with the sharpie a killer quote from a rock n' roll song. you pretty much have one shot at this so practice on scrap paper before commiting.
With the glue gun, attach your embellishments [I like glitter].
Here's another example for all the Dead-Heads.