G'Day
For crabbing the ideal is a run in tide, about 9 - 9.30 am, bigger tide the better, but, you can work the runout on the same sort of tide, on the water pots/dillies down at daylight.
New and full moon periods.
Work your pots/dillies ( soon to be banned ) in gutters or drop offs from banks/reef areas.
I start down here in October, may be a little different up there.
Whole mullet cut in half or whiting frames will do it.
PS: Talking about Sandies
Good luck
Cheers
Bill