Line diameter will make a Big difference. Thicker the line the more water resistance and the higher the bait will rise. Length of line out will also make a difference. Thats why most serious long liners use line counter reels. Next is your electronics to maintain the correct speed and depth. Best advise I can give you is troll a beach area when no swimmers are there. Find the length of line,speed and what weight jigs will hit the bottom, then write it down. The bottom should be fairly level and no snags at the beach.. Also the trailers(grubs) will make a difference as to depth the jig will run per speed. Jig head designs also make a difference. A lot of time,trial and error, but it will pay off later for you.