There's no formal rules for scoring, but the best words to find are:
- As short as possible
- Interesting and unusual, not everyday
- Don't start with the first letter
- Avoid as much as possible having the provided letters adjacent, especially doubled letters (e.g., ANN is better solved with CANYON than BANNED)
There's rarely a drive, even a short one, where I don't do this at least once. It's almost a twitch. Of course in Vermont the game is somewhat limited since the plates that are three letters and three numbers are only up to starting with F or G, so your first letter is somewhat limited.
By the way, for the pictured plate, I'd probably use BACKWARD or PACKAGE.