Well you've come to the right place for the best info!
The first thing I would say is don't try and cram too much in!
If you've only got 3 days, then I would recommend Starting at Torquay or Anglesea and maybe go as far as the 12 Apostles.
I would check out Bells Beach, and Split point lighthouse on your first day.
Aireys Inlet is a fave place of mine to stay, so stay there the first night, or Lorne if you want a bit more dining options.
The second day, maybe erskine falls and Lorne foreshore in the morning, then Cape Otway in the afternoon (allow 1.5 hrs drive to get there)
then maybe back to Apollo Bay for the second night.
Your last day could be more a casual drive to the 12 Apostles, stopping at Castle Cove, Lavers Hill for lunch, Gibson's Steps and Gibson's Beach, and finally arrive at the 12 Apostles in time for sunset!
If you have a third night to stay, then Port Campbell would be a nice quiet night before going home in the morning.
