I'm sure there are many excellent ways to fall upon stopping in clipless pedals, but I'd recommend falling sideways into a hedge in the middle of a large charity ride.

The hedge, while scratchy, prevents any serious injury such as might occur if the elbow joint struck the ground.

The large charity ride ensures that many other rides, as laughing subsides, assure you that it is normal to fall like that. Some might even have funnier stories to distract from the discomfort and embarrassment.