Wind knots are the bane of the spinning reel surfcaster.  They put a screeching halt to fishing and if they cannot be picked apart cause large amounts of line loss.  They occur when using spectra BRAID (Fireline is NOT braid).  Actually, the term wind knot has become a garbage can term for several types of knots that occur during the cast. 

The first and most common wind knot appears as a series of long twisted loops usually occurring in the line toward the end of the length of cast.  They look like this:

This happens when the line that is peeling off the spool catches on a spool face line crossing or a very slack spooling wrap.  Here is a picture of a spool face crossing

The outgoing line will snag on the crossed spool face line and prematurely pull the underlying line wraps off.  This results in a mess that head out with the lure.  The solution is to avoid spool face crossings.  They happen on the previous cast when the initially slack line does not immediately slide into the bail roller and the wraps are guided by the middle of the bail wire until the line becomes taut.  This happens most often when using the automatic bail closure to close the bail.  It also happens when the direction of the wind causes slack line quirks between the time of lure splashdown and bail closure.   Sometimes an outgoing wind knot will catch one of its loops on a rod guide.  The line will abuptly snap off and it's actually possible to damage a guide this way.  Fishermen are mystified why their line broke but it all was a sequla of an outgoing wind knot.  Here are some solutions:

1) Disable the automatic bail closure.  Automatic bail closures inaccurately pick up the line (esp. with slack line) and cause spool crossings.  You can disable the auto bail closure on most reels by removing the small plate on the side of the bail arm and removing the linkage.  

Removing the auto bail closure linkage. (Note- Some reels use a protruding knob on the reel stem to hit the bail arm and auto close the bail.  The only solution in this case is to saw off the knob. Ouch!)

The bail will still be spring-loaded and you can flip it over with a touch of the finger.  If you cup the line with your hand when you flip the bail you can also remove line slack and help guide the first wrap.  Another LARGE advantage of disabling the auto bail closure is it will never snap shut during the cast and crack off your lure!

Proper hand position during manual bail closure.  A touch of the fingers closes the spring-loaded bail and the hand cups and tenses the line at the moment of closure.

2) Visually or by feel verify that there is not a spool face line crossing before each cast.  It’s kind of a pain but about the time you get lazy it will happen.

3) Adjust your bail arm / spool height.  Some reels suffer from spooling line in a non- equal manner.  This can result in a line “shelf” that is more prone to being prematurely pulled off the spool.  Ideally the spooled line will form a straight profile.

Here is a picture of a reel that needs the spool height adjusted.  Notice the line is preferentially spooled near the lip causing a bump (or shelf) there and there is a depression at the bottom of the spool

Here is a picture of the same reel with the spool height adjusted by placing a few simple hardware store washers under the spool.  Notice the line profile is more straight and without shelves or depressions.

4)  Some reels have tall and square drag knobs that can catch the initial wrap of line causing line spooling errors (thus wind knots). 

It's of significant benefit to grind off the drag knob ears and fair things out with body putty or epoxy putty.  Like so:

If you are having random and mysterious wind knots it may be because your loose (initial line wrap) is catching on your drag knob.  Change the orientation of your drag knob and/or do some reshaping of your drag knob.

4)  It's very advantageous in terms of avoiding wind knots to cast with the reel spool fully extended.  There are two ways to make this adjustment before each cast.  You can assume your usual amount of line drop.  If the reel spool is in its low (incorrect) position, pull off some drag and crank the lure back into it's original amount of line drop. Your reel spool will be in a higher position.  Or, you can crank your line in past your normal line drop until the reel spool is in its high position.  Then quickly bump your bail open and shut until the desired amount of line drop is achieved.

Low (wrong) reel spool position:

High (correct) reel spool position:

If you are have random and mysterious wind knot episodes be aware of your reel spool positon before casting.

A similar type of wind knot can happen when the line is VERY loosely spooled.  This can happen when reeling in slack line or sometimes when popping a lure with large amounts of slack between pops.  Here are some solutions:

1) Pinch the line with your fingers to create some tension on the line when reeling in slack.

2) Adjust your rod timing with popping lures so you are reeling at the proper times to avoid excess slack.

3) Use appropriate reels for braid.  Cross wrapping reels do a lot to relieve problems with loose spooling.  Each wrap locks down the wraps underneath it.