[smurfgirl]

Pictures are always good: whatever you want; it could be your robot, the drive team with the robot, the crowd in the stands, someone on your team just looking like they're having fun

If you're using the poster for recruitment purposes, include something that says it's a robotics team, when you meet, where you meet

Put in your team number since that's part of your identity

Maybe add in the FIRST logo (make sure you follow the rules about logo use though)

Above all, just have fun with it- it's your poster, so you can turn it into whatever you want it to and use it to make whatever statement you like. Just keep it postive.