You might want to pick up a book on pruning. Arborvitae don't need much, but
I seem to recall reading years ago that there are some tricks by which you
can get them to stay bushy near the ground so the hedge is as opaque as
possible.

Good idea not only for this hedge, but for everything else. I still
don't feel comfortable pruning as I always feel like only kind of know
what I am doing. I don't think I've actually killed anything yet, but
I've probably stunted more than my fair share.

Thanks,

Mike