For a friend I booked:
Route: SFO-SYD and return
Date: 2/2 and 2/10
Fare class: economy saver to PN
How many days/weeks in advance: At booking a month in advance
For me and my family (4 in total):
Route: SFO-FRA and LHR-SFO
Date: 6/25 and 7/7
Fare class: Economy (I think V - can't tell in the reservation) to PN
How many days/weeks in advance: At booking 6 months in advance