Strange how there has been no response to your post, Shaun. Would like to know the answer myself.

One method I have heard of --- but cannot vouch for --- is to rate the top six runners and then to pair the top rated with the other five; and the second rated with the other five (including the top rated). Cost $10.00.

Of course the top-rated tend to be short -- so you would be lucky to get much over your money back. Though yesterday at Canterbury (taking the top-rated from the pre-post price in the SMH) you would have snared a $44.60 quinella; and in race 4 at Balaklava a $28.50 quinella.