What training method would be appropriate to include in a goal keeper training principle(netball)

It's very important to work on mental reflex training here are 2 exercises you can do to increase your eye reflexes allowing you to see the ball coming at you much quicker I'm a boxer and this would work in your advantage

Hold a pen out at arms length, now look across the room about 20 feet away. Shift your focus from a far object, then back to the pen several times quickly. Rest and repeat, changing the proximity of the pen (closer to your face) every couple of sets. This is known as shifting.

The next drill is called figure 8's. Hold your thumb up at arms length & begin moving it in yes, figure 8's. While you're doing this also bring your thumb closer and farther from the face a well as vary the speed at which your thumb moves every 10 seconds.