Conduct a training exercise with a buddy and an airsoft pistol. He has a stun gun instead of a knife, and you have to defend before you draw. Work your way up to a certain comfort level then make it an all out deal. At a comfortable level you understand where it comes from and how to react, it's the learning side. Then jump into full speed. This is for close ranges.
At longer ranges, within self defense standards, have the buddy behind you with the stun gun and when you miss get a slight... Well, prod. Let's face it, the real threat in self defense is harm, make that why you train. We are animals, we learn from painful experiences. Start the drill slow, draw and fire. When you miss, get a spark. Next, draw, shoot, move, shoot. Miss, get a spark. Make the drill change every time. It helps if you hear the sound of the threat...