Oh yeah... Try the old scenic highway for some great photo opportunities. Somewhere along the line there's some kind of Catholic sanctuary place (I can't remember what it's called) which is very serene and beautiful.
Plus Bonneville dam makes for great industrial/nature shots.
And yes, Peter Iredale is a ton of fun...
Places to visit in Astoria:
-Cannery Pier Hotel
-Flavel House
-Columbia River Maritime Museum
-Docks and piers for all the sea lions your eyes can feast upon
-Astoria Column
-Various lighthouses in the area
But maybe I'm off course and you already know all of this since you asked for technique advice
Sorry.
If it were me I would shoot Velvia for color and definitely TMax for B&W (I think the deep blacks of TMax would benefit the coast) but what do I know