This is the only thing that I have seen on youtube that is worth anything. All of these methods work.
http://www.youtube.com/watch?v=DA5e8d2JPBg
When someone tries to evade your attack and angle. That's one of your best opportunities to throw a dragon tail (sweep or high kick). They will step deeper into you if you have good skills for cutting off the ring or fighting area.
I have had great success with the dragon tail sweep just off of a jab, jab, cross, hook, or jab-hook (same hand).
You can also land the spinning back kick at close range. If I recall, there was a guy, "Bad" Brad Hefton, in the old P.K.A kickboxing who would get into an exchange and then step across his opponent and land a right back kick. Elbows can work the same way especially if you can vary the angles.