QANTAS (QF/QFA):
Domestic, within AU -
List for a flight by calling any QF res office up to 8 hours before flight.
Check-in at any Y counter at the terminal. You will be processed as checked-in, but then will have to go to the Customer Service desk (all located airside, beyond security) where they process stand-by's/nonrevs on a flight by flight basis. (This keeps the gate lounges and gate agents free to worry about the pax and loading, without extra distractions of nonrev loading/sorting).
International -
List by calling QF res before travel.
Check-in at the terminals at a Y counter.
(In SYD, there is a special "RED S" counter purely for non-revs where you check in).
You do NOT pass security or any immigration checks, as you will be called up by name to the service desk area of the check-in counters if you clear for the flight. Only then can you proceed to gate past security etc.

Upgrades:
QF do *NOT* upgrade. If you have an ID50 firm for J or F (pending the interline agreement, these are rare for F) or are on a Boarding Priority that allows upgrade (again, very limited and normally Duty related travel) then you have the right to expect J.
QF until recently did not even allow it's own staff to upgrade until they had 15 years of service minimum, and then you had to buy a special J staff travel fare.

AIR CANADA (AC/ACA) -
List with Reservations.
Check In at normal Y counters.
The counter staff will tell you if you are to remain near the service desk at the counter or go to the gate area for clearance.
Upgrades are rare, and not according to policy, however they do happen. Right place at the right time sort of thing.