Are you getting wind knots (caused by a crosswind) like this:
Or are you having twisted line causing tangles? If you line is coming off your spool and just creating a large wad of tangles you could have a combination of an over-filled spool and twisted line. If your line is twisted (I know the following sounds crazy but it works) take your rod & reel out to a very large park. Start at one end of the park, open the bail and lay the line out on the ground and walk in one direction in one long line. Lay out at least 3/4 of your spool, then close the bail and walk dragging the line along the ground (preferably grass) for at least twice as far as your laid out line length. What this will do is allow your line twist to uncoil as it works it's way through the grass while you walk. You may need to do this a few times depending on how twisted your line is.
This also works on the water if you have access to a boat.