Slightly simpler is the clip pickup, which is a little clip that you can put on a tuning peg or some other metal part of the harp. The sound waves travel through the clip, down the wire, and into your tuner. Another great trick is to get a microphone and place it inside of your harp. Of course you should feel free to use your ears all along the way to zero in on the correct pitch. But in a pinch, a little technological assistance is much better than tuning your harp poorly.
Most ensembles do.
Consider holding a business meeting before or after the rehearsal to discuss future rehearsals, choosing repertoire, potential performances, and all of the other minutiae that keeps a harp ensemble going. Resist the temptation to intersperse these discussions in the playing portion of the rehearsal so that you can keep everyone's mind on the music. Since time is precious it is important to learn good rehearsal techniques that will help the ensemble improve. For many of us, it is hard enough to improve our own playing. Last March, I was privileged to attend Kathleen Bride's harp ensemble workshops at the Baltimore Harpfest 1999.