Interesting thread... I've found that there are about as many ways to cut and hook herring as there are fishermen. I use several depending upon how I want the bait to fish. I tend to prefer a cut leaning more to the perpendicular. I like about a 30 degree cut both vertically and horizontally because of where I fish and how I fish. More angle and the bait tends to pull off.
I will say that on a slow drift in slow water, the big, wide circle seems to be better for kings, but if I'm doing that, I'll cut a spinner instead. For plug cut herring, I like a tighter roll, and yes, this does catch a lot of kings.
For hook ups, I like to run both hooks through the shorter side in the upper corner of the bait all the way through. Then, if I'm fishing kings, I hook both hooks into the bait on the long side. If I'm fishing for blackmouth, I tend to let the tail hook fly. I feel like I get more hook-ups that way as smaller fish tend to be on the move, but kings are more deliberate.
Hook size depends on bait size. 2/0 and 1/0 are pretty standard unless I'm using larger bait at which point I will use 4s and 3s or 3s and 2s. For the quick-and-dirty charterboat hook-up. I would use the larger hooks. For winter fishing, I tend to fish 1/0 as the largest. The winter before last I used only #1 Gamakatsus.
The rock salt is a good idea, but lately I've been adding Alpo
. I'm going to look into the Pro-Cure additives as the frozen bait I've seen around here is pretty poor quality, and the stuff I net is still too small.