Here are a few ideas:-
1. Instant choir. Call members as choristers (an official calling from the Bishopric), choose really easy hymns and let the choristers know when and what they’ll be singing. Have a quick rehearsal beforehand, then off you go. You need relatively good, reliable people to pull this off, but I have seen it done numerous times.
2. Weekly rehearsals mass choir. You choose a time convenient to all, and practice once a week for a specified time. You could have a mix and mingle afterwards. Depending on the strength and capability of your choir, you could perform either monthly or bi-monthly (three times a month if you’re very bold and have very basic matieral).
3. Half hour practice before/after church in the chapel. We did this one year as we couldn’t meet together any other time. We had a double quartet anyway and weren’t too bad. I had simple hymns with interesting arrangements, or ones that were just dead easy to sing, and we were able to sing monthly in Sacrament meeting.
4. Meet at some one’s home with lots of baked goodies afterwards (I raided the cheesecake shop). I think that was the year I actually put on some weight And the year we had the best choir turnout!
5. Same as above, but skip rehearsals completely on Fast Sunday. You have to make sure you schedule your choir items at the end of the month.
6. Alternating men and women. One month have the menfolk sing. The next have the women sing. This is separate to having Relief Society or Priesthood singing as a group en masse.
7. If you have enough, organise a Primary Choir. Have them as an occasional choir, singing songs from the Primary Songbook. I find it’s usually better just assigning Primary a song early enough in the year so it doesn’t interfere with the Presentation, or do “Primary’s Choice” – leave the decision of what they would like to do up to them. They could test drive something they are working on for the Primary Presentation this way.
8. Almost the same idea as the Primary choir, but have a youth choir instead. They are very busy with Seminary and Mutual but getting them together on occasion shouldn’t be too much (I’m talking maybe 3 times a year).
Always let your choir members know how much they are valued and appreciated.
If possible, get your Bishopric involved with the choir, even so far as singing in it.