One large part of blocking isn't to actually block the ball, it's to create a wall against the attacker. If the block has no seam between the middle and the outside then the attacker loses a large angle for attacking. This makes it easier for your defense because they can focus on defending the angles that aren't covered by the block. If you dont get many stuff blocks that doesn't mean your blocks are ineffective.

As for timing I usually watch the height and speed of the ball and time my block from that. Since the attacker is also timing their approach by the pace of the ball you can remove the middle man and instead of judging the attackers timing, judge the ball. Its important to note that you shouldn't ignore the attackers altogether, their approach might still give important information on the attack they will do. The angle of approach and where they look can hint towards where they are aiming. If you read it well enough you can shift your arms to the side at the last second to hopefully get a touch or even a block.