I've noticed some people measure leader length from the rear hook to the bottom of the flasher blade. Others measure from the nose of the hootchie to the swivel on the bottom of the flasher blade.

How do you measure? When you look at the lure action beside the boat what do you look for?

My boat really needs a kicker - it simply doesn't troll down. My downrigger angle runs about 55 to 60 degrees if I'm down about 60 feet. The GPS says 3.6 to 4.6 mph but that may not mean much given current, wind, accuracy of GPS etc. Of course heading into the tide current the speed drops way back to 1.75 to 2.5 mph and the downrigger angle goes down to 40 or 45 degrees. Usually I try to go with the tide tho.

For some reason I get more fish with an old fashioned metal 12 inch Silver Horde flasher as compared to the plastic flashers most people are using. This may be related to troll speed.

With flies I've used a 18 inche leader length on a 12 inch metal flasher measured from nose of the fly to swivel on flasher with good success on the coho.