The Olympic Kick is a talent that some players can have, to score directly from a corner kick.
To get most of it, place two high control players in the two red squares seen in the picture. You'll try to win the control/push battle (a basic feature in corner kicks) and occupy these two squares. As any time the olympic kick has to go through a defender (and the GK), it costs one level of the talent, lowering it, possibly even making it an automatic fail.

In this exact picture, the corner taker has level 2 Olympic Kick, but GK has level 1 Playing Out, the counter to Olympic Kick. So, it shows the power of the OK as 1.

Most players when learning the basics of the game, use a very simple placement of their players on offense corner kicks, one player on near post, another in the middle box, and cross, pass or lob. And this works fine enough, often enough.

I'm giving some other, possibly better options, to make most of your players, and maybe counter their weaknesses.

Note: For a player to be able to header the ball from outside the penalty box, they need to have at least level 1 Head Play talent.

Players who are placed outside the box in the three middle rows, can't be control-pushed away from those squares. This makes it possible to get an almost assured header attempt on corner kicks.
You'll still need to win the cross roll and the header roll, but you'll never get pushed out of position.

Headers from outside the box come with a distance penalty, which will make them less powerful than heading inside the box. So, this is best used with players that have relatively high Head Play talent, but too low control, that you don't want to risk them getting pushed out of position.

You'll see the CPU use this same tactic quite often.

If you have a player who is good at headers and has decent enough control to challenge the push. And you have another player who is also good at headers, but has low control and gets pushed away a lot. Or if you simply want to target your best header guy, but want a bit of insurance against the push roll.

Stack your two players, one on the near post, other behind him outside the box. If the guy on the near post wins the control roll, he'll take the header. But if he gets pushed out, the guy behind him will take it.

Sometimes you might be in a situation where a header from a corner kick isn't a good option. Maybe you don't have anyone who is good at headers, or you don't want to risk bringing a defender up. But you might have really good shooter with high accuracy. Attacking midfielders (AM) are the perfect choice here, because their shooting distance penalty is halved.

Other general tip is the back post decoy. This player is placed on the back post to draw defenders away from the middle, to try and get a cleaner shot at goal. The CPU will always consider this player dangerous and push him, even though you'll never ever actually pass to him.

These screenshots were created in the hotseat mode. The defenders are sometimes positioned as I personally would position them to defend the corner, and sometimes how I expect the CPU to position them (I've played this game enough to know what the CPU will most likely do in most situations). How the CPU will actually place its defenders in true game situations will vary.

And there is a player in couple of those pictures I've marked as "Ignore this guy". He is a CF that hasn't been moved, but still gets to make play on the header, if the others miss. So, maybe don't completely ignore him, but notice how you can have more than two players get a header roll on corners simply by your initial formation.

And these aren't the only ones. Some specific situations might require thinking about specific solutions. Corner kicks are some of the best chances to score, so it's well worth it to experiment and learn to make most of every chance.