You didn’t mention if you are fishing with a boat. There are a lot more options open to you if you are. There are a lot of very shallow areas in the lake, so my advice would be to go to Marine Rescue at Forster and get a chart of the lake for about $7, and take a lot of notice of the port and starboard markers, and you sounder. The channels are generally 4+ meters, but a large portion of the lake is less than 1 meter, and plenty of areas are only 0.3 of a meter. The biggest challenge is to work out the tides. The water moves quickly in the deep channels, with little slack water between the outgoing and incoming tides.
The best boat ramp to launch from is at the Forster boat harbour, a short distance from Marine Rescue. It is fairly well protected from the quick flowing tides, and the washing facilities are great. Other boat ramps can be difficult when the tide is flowing quickly, although the ramp at one of the caravan parks has little tidal influence, but you need to be staying at the caravan park to access it.
The breakwalls have been producing kingies of late, mainly using live bait. Fish the breakwalls on the top, or bottom, of the tide. Generally the water slows down about 2 hours after high or low tide. i.e. if high tide is at 7.00 am, the water will be stationary at about 9.00am (depending on the difference in height between the high and low tide that day).
This time of the year you should get amongst the flatties almost anywhere, but there are a lot of small flatties in the system as well. Soft plastics will generally get results. Bream can be caught around the oyster leases, but again it can be a challenge to be there at the right times, until you have the tides off pat. Whiting are still being caught on the sand flats.
As Badsanta mentioned the Wallamba (and the Coolongolook River) can produce well, but be aware that there are plenty of speed boats around at this time of the year, particularly near the caravan park in Aquatic Road. Early morning starts will help avoid them and most of the jet skis.