In rivers, even tidal areas, especially in the clear water we have now, think small and sparse for salmon; kings, silvers, pinks, whatever. You can hold a very large fish on size 6-10 flies. This has been known by California anglers in the Smith River for years. Haig-Brown wrote about the success of small flies on salmon in Fisherman's Fall in 1964.
The primary advantage of small, sparse patterns is that when tied on a short leader they will sink readily. If you employ weighted eyes, small bead chain is usually enough. The other important fact is that you rarely -- if ever -- will snag a salmon when you employ flies with small hooks. The bites will be solid and the hookups will be in the jaw.

Good Luck,

Les Johnson