Heading a soccer ball is another way to pass the ball to your teammate or use it as an option to score.
To head a soccer ball you want to make sure that you use your hair line. Start of your hair line is usually the are of the head to use to actually hit the ball in a way it does not hurt. When you want to hit the soccer ball, head the soccer ball, you want to make sure that your hands, your arms are up because you need protection on the side.
You don't want to make the position head to head with the other guy or player on the field once you get to the ball the position is made with your upper body. If you get to the ball first or the other one. So arms up is a good idea to make sure that you will be the one heading the ball.
Another one point to consider is the feet are not next to each other. One is in front, one is in back because you want to lean back and use the entire momentum coming from your upper body with one foot in the back giving you enough cushioning to actually accelerate on the way forward and head the ball.
If you want to head the ball in an angle, ideally you don't use the side of your head, you want to turn over and again have the chest and the head, the face, the eyes facing the player or the open space where you want to head the ball. So it's never sideways. It's always or in 90 percent of the cases forward with the hairline, you aim at the player, you aim at the open space and you have your head, your neck is locked, it's not the head that is moving, it's the entire body where you get the momentum and the power from.
That's a good way to head the ball. Keep working on it.