I usually use 6 pound line for crappie magnets. I use 2 pound for trout magnets. I usually use a straight retrive at the depth the fish want it. For some reason the fish really like the gliding action they provide. Bluegill with the trout magnet l I will use the twitch method like the one showed in the video.
http://troutmagnet.com/video-detail.php?id=5