Depends on how fast you want to get there... The prettiest way would be to go through Corrimal, and then follow the old road through Bulli, and then go over the ocean road (Hargeaves Drive) to Sublime Point, then follow Highway 6. The quickest way is simply to follow the Princes Highway (6) straight up. There is another way as well - Bulli Pass. Both the latter are OK, bu the former is by by far the prettiest way.
Go up mount ousely turn left at the bottom of mount ousley into Picton road follow it until you strike the turnoff to the motorway to Sydney you will be turning right,then keep on it until you see signs to Newcastle then follow them till you get. On the expressway and it will take you right up the north coast.I live on the sout coast and this is the best way bully is slower and steeper in my opinion...
We did the picturesque coastal route from the Royal National Park, down the Grand Pacific Drive (Sea Cliff Drive) and into Wollongong from the north side. Towing a 21' caravan. No worries for us. (http://www.grandpacificdrive.com.au/)
Depends on whether you are in a hurry or not. Regardless of which way you travel you will have a climb at some stage.
another vote for Mt Ousley but take it easy, 2 truck crashes this week have closed it for several hours, as dogbox sais Bulli pass is closed for maintenance and more traffic on both the coast rd and Ousley means they are very busy