We just used a lure. So assuming you can already have her sitting by your side I just turn 90 degrees and lure her round, and reward when she turns and sits. I've seen other people on line training it with a kiddy toilet step but I don't know how that works tbh.
In the garden I can use a food lure, out and about I lure with the tennis ball (I do a few reps then throw the ball as the reward).
Clockwise was straightforward, counter clockwise has taken quite a bit of work.
This is where we're at right now
flic.kr/p/2nELJxz
Finish is still a bit too enthusiastic!
flic.kr/p/2nERNHp