This is recommended, because it obscures your IP-address. It conducts
a meta-search, possibly on multiple search-engines, or just on one.
(They change their strategy from time to time, and vary geographically as well).
Here is some guidance on how to compose more complex queries
This is also recommended, because it's a proxy-server that searches on Google, but obscures your IP-address.
This may fail on some browsers, particularly older ones. If so, you can use Startpage's Advanced Search page, by putting privacy.org.au in the "site or domain" field.
This is NOT recommended, but is made available for anyone who wants it. It has the largest catchment of any of the search-engine services, but is highly privacy-invasive and consumer-manipulative.
Alternatively, you can use Google's Advanced Search page, by putting privacy.org.au in the "site or domain" field.