Usually the sign that gets the most amount of attention is a sign that has movement. A waving flag banner that is blowing in the wind usually attracts attention. But you don't want it moving so much that people can't read it. A sign holder who holds a sign on a street corner gets a lot of attention. If they can dance around with the sign, but you are still able to read it, then that's a great sign holder! Foamboard, gatorboard and PVC all make great signs for this and they can be cut into any shape or size. A backlit film sign in a lightbox has light to it so it will attract a lot of attention, most at night.