The ATC at Amberley are pretty friendly, however if you wish to remain OCTA all the way, track in via ESK then either towards Dayboro or Caboolture direction and follow the VTC towards the VFR entry lane at the west of Mount Coot-tha, reporting "AT TV Towers at 1500'. This is pretty easy to find. Next reporting point is the bridgeover the river and on into YBAF. They guys at YBAF will be helpful especially if you declare you are not familiar with the airfield.
If cloud is low you can track from out near Kilcoy to Caboolture along the D'Agular Highway and then skirt through the north west of Brisbane that way.
Other options are to use YCAB (No fees) or YRED (almost no fees).
Cheers and happy flying!
J