On riggers I would go with a clean spoon with 20 ft of lead out and one cut bait or whole herring on an 11" paddle, with about 40 to 50" of leader between flasher and spoon, and 20 ft of lead out from cable.
On divers I would use flashers and flies. I don't ever use flasher and spoon. Spoon doesn't need the action of a flasher.
In terms of depths, you should as a minimum check out this site and determine what depth you want to be in. You want to be fishing in 42F to 48F water. If you can find a slice that's around 30 ft thick with 42F on bottom and 48F on top, that's great.
Speed at 2.5 mph average but try changing between 2.2 and 3.0 mph until you generate hits. Remember hits in one direction, may not mean hits in the other direction. Normally if I get hits I confirm depth of line, speed and direction, and color/bait. I then repeat, repeat, repeat.