When I am cooking salmon I also like to include some cedar branches in the fire for some added flavour from the smoke that comes off of it when it burns. Cedar in particular has a fairly strong odor to it.
When grilling on a hot grill, I like to cook each side about halfway through then rotate (not turn over, yet) the fish 45 to 90 degrees, let it finish, then flip it and rotate it once again. The resulting cross-hatched grill marks add lots of additional flavor like you mention.
I also do the rotation method for most meats cuz I love those flavored grill marks. Make sure not to have too hot of a fire or the outside won't have marks, it'll just be a black burn.
You might try using "Seasoned Pepper" with your recipe (not just black pepper). It's a pepper blend put out by Schilling that adds a variety of pepper flavors, including black pepper, to your fish.
Man, you're making me real hungry for grilling up some fish on the Barbee.