Goalie play is about efficiency of movement and reducing the angle by which the shooter can get the ball past you into the net. As a goalie, you want to start in an athletic stance and in a natural position in the center of the goal.
Further reduce the chances of the ball getting past you by stepping at a 45-degree angle toward the path of the ball.
If a shooter is on the right side of the goal and shoots toward your right side, you want to step in a 45-degree angle toward the ball. Lead with your right foot and close with your left foot, staying in good athletic position to take up more surface area of the cage. Remember to step toward the ball, rather than toward the shooter.
Similarly, if the shot comes to the left side, step with your left foot at a 45-degree angle and close with your right foot.
You should always focus on your positioning in front of the goal. Move with the ball, not the attacker. As a shot comes in, move toward it. You want to take away as much area as you can so that the ball has less of a chance to get behind you into the net. To help develop this skill even more, practice the “Walking the Line” drill.