[JYang]

First lay out the basics of what you want: whose the audience, what information do you want to put on it, where is it going to determine size etc.

Afterwards, think of things that represent your team or robotics/FIRST in general. Pick 3 items/pictures at most and just play around with size and ideas until you have something that everyone likes. Just remember, KISS it attracts attention that way, especially if people are rushing by it.