if you are talking about spinning reels, the key to avoiding those birdnests is to put your line on opposite of how it comes off the spool when you cast it. As it comes off my spinning rod (counter clockwise). So when I change the spool of line, I have it come off of the spool on to the reel clockwise. That should fix the problem. The other thing you must do is make sure that when you cast, you close the bail manually with your hand, because loops get on the spool, and that will lead to line twists. Hope that helps.