The food some are referring to is fresh fruit and vegetables. Yes declare everyting, but if you are used to brining bars, or nuts or snacks, that should be no problem. Also, if you have a passport with a chip, you can use the smargate electronic readers in Australia and NZ... faster, sometimes, but no stamp in your passport. I would do the ETA yourself, its very easy, just make sure you are on the official Australian government site, and not a visa provider, who will charge you more. Where are you going ... both are wonderful and different enjoyable experiences. Enjoyed them both many times.