Team 811 has given varsity letters for many years; the standard that we follow involves a student who has been on the team for at least two years, is a junior or senior in school, made significant contributions to the team and/or robot, regularly shows leadership in the team, and has the endorsement of the mentors on the team.
A number of years ago we had pins made for us by the
Aaron Label Pin and Button company. Their 1" square cloisonne pints cost us about $2.75 apiece (for 100), and they're gorgeous! Here's a slightly oversized image of what they look like:
If anyone's interested I can help you do your own.