Back in the 90s I used to fly to Aus about 8 times a year. After various experiments, I found that the worst trip was Aus to UK straight thru. Whenever possible, I did not do that, and stopped over for 2 or 3 nights in Singapore. I tried 2 stops and 3 stops on the Aus to UK route, but found no real extra benefit, so one 2 or 3 night stop was the best for me.
Going from UK to Aus, I found that going straight through was my best approach. Stopovers didn't seem to help. I would just get there, and then try to rest/be a tourist (rather than work) for at least 24 hours.