Downriggin has an impressive list of leader lengths based on his log. That is a great piece of advise for all...keep a log. If I had only done so in the last 25 years what a book I could write too. Alot of my initial techniques were handed down to me by my uncles who lived on the water in area 8-1 and 7. I have developed my own techniques for success and will pass on a couple of them..........
First I think the combination of presentation and boat handling is the key. After I select the gear and get the lines ready to go I then have to select the depths to run the gear and then , in my mond, the real key is the handling of the boat. What I mean by that is the water covered , the trolling pattern as in twists and turns and then the real important element SPEED...This combination was really proven this year at Westport and Neah Bay. I use my Garmin GPS with huge numbers settings to observe the speed in knots. I pay close attention to the action of the lures at any given place and time and at different speeds. This is an aquired technique that can't be learned on the internet. Alot of folks simply look at the downrigger cable to see if it has the "right" angle and go by that . I saw this on my own boat at Westport recently...I usually drive but gave up the wheel for awhile and watched the downrigger cable angle technique. We caught few if any fish. I took the helm back and adjusted the speed and started making turns at different speeds and bingo two kings 33 and 34. This was using 6" spoons.
One other interesting thing: When I was a teenager my uncles used to take me to Sekiu and here is the ONLY thing that worked according to them:
Abe n Al silver flasher with 18" (exactly) of 50# mono leader to a blue and white hootchie. A length of 50# mono about 6' long from the flasher up to a triple swivel and the main line...a dropper lead off the swivel...That was it...fished 50 feet down in 60' of water and nailed the kings....yes kings...with 18" of leader.
I also caught the most hook nose silvers on Possession using the following:
GloWhite Silver Horde F4 Piscator metal flasher
22.5" of 50# mono to a squid called "Apple Core" with a twinkle skirt....Two 5/0 sharp hooks with the trailing hook just barely below the bottom of the squid. Fish the bar at 100-150 down when you can spot the schools migrating at that depths.
And finally the Coyote....I have used 72" of leader behind a Hot Spot for kings and had the most success by far. This also is done by combining the driving techniques of varying speed and making turns. When the 72" of leader goes around a corner on an inside turn the spoon will flutter and slow down causing the fish that may be following it to strike. This really worked with the 6" spoons with no flasher.
To each his own....Remember that you usually catch 90% of your fish with what you use 90% of the time. Try something new and you might be surprised.