Well here, on Quality Aussies, is a fabulous page on Calming Signals (though unfortunately, the linked Rugaas web sites at the beginning of the page are no longer up). I really know little about Australian Shepherds, and have never interacted with one, but that doesn't matter in this context. These are things that every dog does, naturally. Instinctually.
Now, does every dog listen to the calming signals of others? Even if they're doing some of their own? No, I can't say that they do. I think dogs are rather like people in that regard (or people are like dogs) in that we can miss the messages that are right in front of our faces, and end up making poor decisions.
I've got a good "yawn and head turn" picture of Elka:
The "sideways approach" illustrated by the Quality Aussies is one that I do frequently with a library patron's dog. She's a little mini Aussie-Border Collie cross (okay, so I've interacted with half an Aussie), and she's demonstrated herself to be rather fearful. So, I sideways approach. I turn my head. I let her come to me. Typically, she'll wiggle over to me, and then turn her back to me and sit. Then she looks at me, grunt-whining, and I scratch her rump and haunches, which makes her get up again and close her eyes with happiness.
Really, I'm jealous of all those great Aussie pictures (though if I'd properly socialized Elka, I'd be able to take pictures of her playing with other dogs. Sigh.) I do have a piloerction one: