I am planning a three-week Sydney and Melbourne trip for 10 September, with employer leave approved but flights still refundable. I feel torn between applying early and risking a booking mismatch, so I want to prepare the passport, funds, itinerary and residence evidence while treating any published processing estimate as uncertain.
Identify the route in the official Visa Finder, submit a complete application with passport, residence, funds, employment, itinerary and purpose consistent, and check the current processing information for that route. Keep flights refundable or delay non-refundable commitments where practical; an estimate is not a promise and a request for more information can add uncertainty. Save the reference, monitor the official account and do not travel before the required permission is granted. Policy and individual handling vary: https://immi.homeaffairs.gov.au/visas/getting-a-visa/visa-finder.