I'm just wondering what to sleep my 1 week old baby in - I'm in Darwin and have my aircon set at 22. Is having her in a onesie, no legs or sleeves and a 1.0 tog swaddle arms in enough? Or should I put a blanket/sheet on top too? Thanks

It is difficult to recommend specific amounts/types of bedding/clothing for each individual baby.
Generally, we suggest dressing baby as you would dress yourself - comfortable.

Red Nose has the following information.
Dress baby and use layers as you would dress or use layers yourself: to be comfortable, neither too hot nor too cold.

Dress baby for sleep and add/remove lightweight blankets to ensure baby’s back or tummy feels comfortably warm to the touch.

Remove hats, bonnets, beanies and hooded clothing from baby’s head as soon as baby is indoors.
https://rednose.org.au/article/bedding-amount-recommended-for-safe-sleep

It is not necessary to monitor the room temperature or to leave the heating or cooling on all night, as long as the baby is dressed appropriately for the room temperature.
https://rednose.org.au/article/room-temperature

You can use a lightweight blanket, but make sure it is tucked in & not likely to come loose.