A lot of this depends on the water level, clarity, how hot the fish are and of course the structure you're fishing. I'll fish the heaviest line I can get away with in the water clarity. My main line for Springers, Steelhead and Coho is 12lb on my medium action spinning rod. I'll run 12 - 20 lb leader for Springers, 6 - 12lb for Steelhead and 6 - 12lb for Coho. Right now on the Clackamas the water clarity is great because it's just slightly dirty. The Coho coming into the lower river are often very hot on the first couple runs but tire quickly. Running 8 or 10lb maxima ultragreen is great on my spinning set up. These fish are lock jawed for the most part at this time. Running spinners can produce an instinctive bite from a fresh coho in the lower river, but mostly what I'm seeing at this time is snagging not catching. #3 - #4 blue fox in a flashy color if it's sunny, or a paint if it's cloudy should do the trick. If the water get's more off color than it is now I wouldn't use a flashy lure, and I might be inclined to bump it up to 12lb to make things easier on myself and the fish. If it was me I might just decide to plunk a slightly bigger rod with heavier mono due to the lack of biters and dispersed population of fish in the river at this time.