Andy of thoughtsON has some excellent points in a blog-post entitled It isn't welcoming if I can't figure out how to get inside.
All of these are excellent pointers for Unitarian congregations who don't want to put off newcomers by our funny quirky little habits.
Additional ones for British Unitarians to think about...
Remember to brief the visiting worship leader about what happens with the collection and the notices and the musical interludes. And bring them a glass of water and tell them where the loo is. (Most people do remember most of these, most of the time.)
If you sing the Lord's Prayer / Prayer of Jesus: not everyone knows the tune, or knows the same tune as you.
Children don't always like being sung out of the sanctuary with the same song. Go Now In Peace can get awfully samey. And don't get me started on that Rumi chant, Ours is no caravan of despair.
Please feel free to add your pet peeves in the comments!