Hmmm... I'm sure you've probably heard or read the basics. A properly setup fighter kite is unstable when held at a neutral tension or releasing line, that is it will spin. Actually when properly tuned and you stall it low to the ground in a nose up position it should "Cobra" (sit and wobble back & forth) at neutral tension. When the nose of the kite is pointed in the direction you want it to go pull in on the line, either hand over hand or with a spool if you choose use one. That causes the bow spar to flex and forms a dihedral allowing the kite to move in a basically straight line. Past that it's pretty much practice to get the feel.
Put a Crepe Paper tail on the kite to start, say 3-4 + feet depending on the kite. It will slow the rotation down significantly and give you straighter flights. Once you are keeping it off the ground rip a third or half off that tail and fly some more. It really helps to get the movements you will be using down with some time to react.
Have you found http://fighterkitecentral.com/
? much good info there, flight basics, tuning, plans and a forum which is still pretty active. I would go spend some time there. (beat me Dromel)
What kind of fighter have you gotten? I really should get back to building some and flying them again.