Warn UPs of things they'll be expected to do or guide them when the time comes. Don't leave them to fumble or wonder what's going on or what's appropriate. If you're going to go around the circle 3 or 5 times with various implements, either have something going on, or overlap. Don't make UPs stand for long periods of time. Think about how the power dance will work.
Surprise can be a very effective ritual element.
C. Religion Most of the religious aspects apply equally to small groups. Before is OK, worked into the content is better. Explain purpose if other than celebration. Make UPs feel welcome. Involve the UPs.