I really suggest that you make at least a small way to score.
If not, the best thing you can do is have a really good bridge actuator, and have the ability to pick up balls and shoot/feed them to your alliance.
If you can't score, then the only reason an alliance will want you is if you can make it easier and faster for them to score, by going around to the other side and feeding excess balls and feeding balls from your alley to them. You also need to be able to work around opponents without getting penalties, and a bit of driver practice, even if it's on Thursday in the practice court. I know I'd choose an alliance partner with those capabilities.
This will make any team a valuable alliance partner. Other helpful things is to have a wide robot chassis so it's easier to fit 3 robots on the bridge in the endgame.
If you ever need any help, please feel free to ask any teams here on CD, especially 256. We're more than happy to help!
