Went to Aus this week - first international business trip in two years. Checking at Palmy on Monday morning (they had 45 international connecting pax on the flight!) I had to produce:
RAT negative test from within 2 hours
International NZ vaccine passport (I had only downloaded the international one, but it is done in two minutes if you can remember the passwords) - it looks just like the domestic passport
An Australian health declaration that asks for dates of your shots
And because I have a UK passport, proof of visa (we don't get the ETA anymore - one year multi-entry visas take 10 days which I almost found out too late)

Coming back I had to show Air NZ in SYD:
My NZ health declaration which has the RAT test result integrated but only 24 hours before (I took one at MEL airport the night before for $59)
International vaccine passport

On arrival at AKL had to hand over my written declaration and got three RAT test kits for testing on day one and day 6.
Masks on at airports and on flights. Spotty use in lounges
Long queues for economy class passengers as checking times take much longer. I saw plenty people (not on NZ) being refused travel (one person denied travel because his RAT test was 25 hours old).
I hope things change as it is a fairly anxious process, especially being tested at both ends and the potential to either have to delay travel or isolate in a foreign country for seven days.
And the fare was $1,800 return in Y. (the Works).