Hi Simon welcome aboard.
I'm from Perth also and have utilised this forum for all my questions so far. So much knowledge gained from years of experience, can't beat it.
I am also a Coopers kit brewer and have tried a few variations and also tried an array of boutique beers but found that I have simple tastes and enjoy lawn mower style beers (and so do my neighbours). I have found that the steps for the greatest improvements are; 1. Sanitation, 2. Temperature Control 3. Choice of Yeast 4. Amount of Yeast Pitched 5. Patience.
Then the down side is, 1. Continuous sampling 2. Continuous brewing 3. Continuous tweaking 4. Continuous buying things(just because) 5. Becoming addicted to brewing. ( could be a positive)
Enjoy.