|A1,2 (8)||Lead up a double and back twice|
|B1 (4)||Back to back|
|B2 (4)||Right hand turn once and a half (3)
Clap together, then right hand, before moving onto the next person (1)
The first time everyone leads up a double and back. Then just first couple back-to-back and turn, clapping on beats 7 and 8, before moving on. Then they dance with a new person on the side (1M with 2W, 1W with 2M), leading out to begin with, finishing moving on as before. In the next change there are three couples dancing, including 2nd couple leading up at the top of the set. This continues until all are dancing.
I like to do it so the first couple go round once and a half, until they meet again at the bottom. Once you're dancing you don't stop.
This can also be adapted for a circle with everyone dancing from the start, which simplifies it a fair bit. It starts with everyone going into the middle of the circle a double and back twice, then continues with a back to back with your partner etc. as before. Or you can do the forward a double and back around the line of the circle instead of into the middle if you wish.