You need to learn to feel comfortable being very close to the net. The reason is that it takes more timing to bring your hands up from your waist, and there is also a risk that you will catch your hand on the bottom of the net. If the live setter is really far from the net, then you know that he won't attack. If your job is to block that setter, you are immediately ready to block another hitter. A blocker must tell his teammates when his attacker disappears behind another attacker.
Fingers spread wide and stiff.
A blocker's fingers are spread wide to take away as much court as possible. The arms should be slightly less than a ball width apart so the ball can't be hit between them. Watch the arm, not the ball. As soon as the ball is set and you can see where it is going, you can take your eyes off of it. Instead, watch the hitter's arm.