Redeeming award flights with Qantas points 11/12 months in advance - Do I redeem as 2 one-ways or a return flight?

Guys need some advice…

Last used my points to go to the US in 2007 and can’t remember the process. I currently have 600,000 points so travel is not the issue. Want to go Business Class too.

Want to book Rome return for next September 2018 and looked that I can book 353 days out. I will be there for 29 days.

Question - do I book outbound leg first 353 days before and then 29 days later book the return?

Or…do I wait 353 days from my return and do the two together?

I tried 353 days from today (return) as an exercise and found plenty of outbound but almost nothing return and only economy??

Any ideas would be appreciated.

Thanks H

With Qantas points, return prices out at the same as two one-ways. So book the first one-way when availability opens, then wait for your return date to appear and then book that as a one-way.