While blue marlin can be taken by drifting live baits (an effective technique around oil and gas platforms in the Gulf of Mexico, as well as around weed-lines, FADs and flotsam), most anglers prefer to troll in order to cover more territory. Trolling speeds will vary depending on the type of bait or lure being used, but usually range from three to nine knots.
Blue marlin are highly susceptible to teasers -- the bigger the better. A variety of commercially made teasers are available, or you can make your own out of wood or even a boat fender. In the old days, some skippers dragged a series of tin cans. A teaser's commotion will definitely increase the number of raised fish.
Dead baits can be simply skipped on top or rigged with a chin weight to make them swim just below the surface. Artificials should swim just below the surface for short period of time, creating a long bubble-stream, before coming to the surface to take another "gulp" of air. Varying sea conditions will require throttle adjustments to achieve the correct lure or bait action.