Spruce beers are one of my seasonal favorites, I usually use about 1oz of tips per gallon.
Just did a dark, with 1# of German smoked malt. 4oz Spruce - 60 min, 2 oz 10 min, 1 oz Cluster (60 min), .5 Tettanger 10min. I use BeerSmith & shoot for a low end IBU & let the spruce take it the rest...