Shielding the ball is when an attacker maintains possession of the ball from a defender who is in close pursuit. While the attacker is shielding the ball, they want to look for passing options. So the first exercise, the attacker wants to keep the ball away from the defender. Key factors to shielding the ball is you want to stay sideways on to the defender. You want to keep your body between the defender and the ball.
You'll want your legs wide with a low stance. The second exercise, we use an eight by eight grid so that the attacker can not run away from the defender. They must stay within the area of the eight by eight grid. You want to keep the ball moving so that you can create openings. You'll want to extend your arms so that you know where the defender is, and make yourself wider. You'll want to keep your head up so you can see the available team mates. The third exercise, we add a serving player who plays the ball into the attacker, the attacker shields the ball from the defender, and then after a few touches he finds his team mate who changes his angle.
Often you'll have the ball with no one to pass to. When you get defensive pressure, learning to shield the ball will help you maintain position until you get support from a team mate.