I think the best thing you could do is to learn a proper double haul. Here a couple of videos to get you started.
If I can give you suggestion, do not try long line pulls at first. The longer the haul, the more line you have to feed back into the cast to get ready for the next haul. So start with short line pulls to get the timing of the haul done, then extend the hauls.
Joan Wulff: The Double Haul | MidCurrent