For an autolyse to be most effective, it would be helpful not only to have a good dough recipe to begin with but to also have some idea as to the absorption rate of the flour you will be using to make the dough. The absorption rate is what the miller specifies as the more or less “optimum” hydration of the flour as determined through laboratory analysis (Farinograph), and is specified as a percentage. For example, for the King Arthur high-gluten flour it is 63%, plus or minus 2%. The absorption rate for an all-purpose flour might be closer to 60%. (By contrast, a cake flour or pastry flour can be around 50%). Knowing numbers like these allows you to have an idea as to how much water to use in relation to the amount of flour. Some millers have spec sheets on their flours that give you the absorption rates, but many do not publicize that information. In those cases, you would have to call the miller and ask for the figures.
Absent the above type of information, you have to experiment with the amount of water for a given amount of flour. From what you have said about Australian flours, this is what you most likely have to do. The way I do it under similar circumstances is to take part of the flour I plan to use in my recipe and add some of the water specified in the recipe. I stir these with a spoon to form a smooth, lump-free, slurry-like mixture. I then continue to add a bit more flour and water, stir, and continue with this process until all the flour is in the bowl but with a small amount of water remaining. All of this can be done by hand in a bowl or work surface or in a mixer. I then add the remaining water incrementally and knead it in to see whether the dough will absorb it. If all the water is fully absorbed and needs more, I add more (and note the amount of additional water). I stop when the dough is a bit moist and tacky and doesn't look like it wants to take on more water. Knowing the total amount of water I used, I can determine an "effective" absorption rate for the flour by dividing the weight of the total water by the weight of the flour I used. That would be the number I would use as a hydration percent the next time I use the same flour.
Turning now to the autolyse, there are many possible variations, even within the original framework set forth by Prof. Calvel. The way I usually do it is to take a portion of the flour and water as specified in my recipe, say, 1/3 to 1/2 of each, and mix together within a bowl. I then cover the bowl and let the mixture (it will be like a slurry) rest for about 15 minutes to a half-hour. This is called the autolyse period. During this period, the flour has time to better absorb the water (hydrate). I then gradually add the rest of the flour along with the remaining water. If I am using IDY, I will add it to the flour; if I am using ADY, I will have proofed it in advance using a small portion of the original water (warm). That gets added to the remaining water. If I am using a preferment, it goes into the water.
I use the same procedure as described above to gradually combine the flour with the water/yeast. Once I am satisfied that the dough is absorbing the water, I add the oil, if my recipe calls for it, and knead that in, and continue kneading until the dough approaches the final condition I am trying to achieve. Finally, I add the salt and knead that in until it is well incorporated. I usually end up doing about a minute of hand kneading to be sure that the dough is in proper condition and to shape it before it goes into its container. If everything falls into place using the above procedure, you should be able to cut short the total knead time by a couple of minutes, which is good for the dough because it reduces the degree of oxidation of the dough (if using a mixer).
In addition to considering the above approach, you should also take a look at the dough processing technique used by pftaylor in making his Raquel dough. The technique is a variation of the classical Calvel autolyse but it works extremely well. It makes one of the best handling doughs I have seen in a home environment. Using whatever Australian flour at your disposal, you may have to do some experimenting, but using the underlying Raquel technique should still be a big help.