My biggest tip for cyclists, look right at the driver of the emergency vehicle if possible once you have stopped. This means the driver knows you have seen them and can safely pass.
Once people look at you, you know they can see you and that makes things much safer for everyone. Oh and please, please, please ensure your safety has far more priority than the progress of the emergency vehicle. Getting killed by trying to get out of the way helps no one and will only delay the emergency vehicle.