Narrabeen should be heating up around now. The flatties are biting around the entrance to deep creek on the flats. A few nice bream and whiting mixed in as well. If i were you, i'd make up a standard mullet rig (float) and head to deep creek. Head around 50-100m upstream, thrown some bread in and fish around it. You should catch loads of mullet doing this. Most are around 2-25cm but last time i got 5 over 30cm biggest 39 and great fun on light gear. Its the best way to ensure you actually catch fish at the moment. Next best bet would be fishing live worms or prawns in the channel at the caravan park. Should be bream, flathead, whiting and tailor atm. Have a go and hopefully they're biting when you do!
Cheers, Tom