Should be possible to fish Kenepuru or Pelerous as day trips from Piction, probably would only take 25-30 minutes to reach the start of the Kenepuru. Can not think of any hot water shower campgrounds in the Kenepuru, although these coldwater showers at titirangi.
Elephant point in Moetapu Bay is nice small beach and point for relaxing fishing. These a small DOC campground there so could be crowded this time of year.
These also 2-3 access points down to the beach just before Ohingaroa Bay. One of them is by a large tree, these a second safer climb a few meters west of the track which goes down near the tree.
Island point. Park at the top of the point and a steep track leads down to Island point. Wet access at high tide.
Plenty of easy to access points between Black rock and Kenepuru Heads.
These one in Te Mahia Bay, buy 95% certain it would be occupied by freedom campers this time of year. The same applies to the cutting near Portage. These also a track down into Broughton Bay, these a needle covered parking spot towards the top of the hill. then a short walk down to the beach. Another option is to follow the road to the beach but probably occupied by campers this time of year.
Bait. I have had most of my luck on Pilchard and Anchovies. But they do not last for long during the day, then freshly caught bait is better. At this time of year I would probably aim to arrive at the fishing spot around 7:30pm and might fish until 10-11pm. Fishing outside that period is generally very slow.
My rig is very simple, just a 8/0 hook snelled onto 2 meters of 40lb trace. I then tie the trace straight onto the mainline. I never use sinkers and just strayline.