Corners: Where To Stand

Most of defending a corner is done before the ball is kicked. If you start in the right place and the right shape, you can reach more of the box.

Catching a cross

On the pitch

Along the line: The middle of the goal, or a little towards the far post. Running forward to the near post is easier than going backwards to the far one.
Off the line: About a yard. Further out for an outswinger, which curls away from you. Closer for an inswinger, which curls towards your goal.
Your shape: Half turned, chest towards the penalty spot, so you can see the taker and the far post.
Your posts: If you have a defender on a post, tell them where you want them, and tell them to step out when the ball is cleared.
Your call: "Keeper's!" if you are coming, and you go all the way. "Away!" if you are staying.

Common mistakes

Standing on the goal line. Every step you have to take is then a step you start late.
Standing square to the corner taker, so you cannot see the far post.
Coming for a ball you cannot reach, and getting stuck under it.
Saying nothing. Your defenders cannot see what you can see.

Practise it with Corner Positions, Take It At The Top, Crowded Box, Punch It.