It is very difficult to provide an accurate answer to this question. The answer could vary from country to country. And it also varies from person to person. There are many specifics. Yet, here is a reasonably decent summary that applies to most nations without exemption.
You can get the Australian Visa application form from the website easily. There is a list of mandatory documents for applying for an Australian Visa Online:
Australian Visa application form completely and legibly filled and signed by the applicant with recent photographs. This can be available online.
Passport/Travel Document must:
Be issued within the previous 10 years, and the validity must not exceed 10 yrs. It should have a validity of 3 months after the date of return. It should have at least 2 standard quality blank pages, not torn, damaged, faded, stapled, etc.
Overseas medical insurance:
For applicants aged 70 years and above, it is necessary to get a declaration duly endorsed by the Overseas Travel Insurance Company on its official letterhead which will highlight that the Insured person is covered for the Emergency hospital, Medical Expenses, and Repatriation expenses.
With travel dates mentioning if any other country/countries are to be covered during the entire trip.
Whether you are from Dubai, China, Russia or Vietnam, you need to download the Australian Visa application form, fill it and submit it with the rest of the documents. Acceptance and rejection of your visa depend on the submission officials, who approve or disapprove of the visa.
Once, you have paid the visa fees, you need to track the visa process via agency website, email or SMS. Then, you can collect the passport when the passport is made available at the agency office or your correspondence address.