In general, the aim of a backheel kick is to pass the ball to a player who is behind you.
In this video, we show you the most common technique for doing a backheel kick, i.e. starting from a stationary, stable position.
The two technical points to focus on for a good backheel kick - and to avoid ending up flat on your back with the ball at your opponent's feet - are the position of your non-kicking foot and the point of contact between your foot and the ball.
To start, place your standing foot, that is, the one you're not passing with, 20 cm to the side of the ball. Stand to the left of the ball if you're going to kick with your right foot, and to the right of the ball if you're going to kick with your left foot.
Next, let's look at the contact point between your foot and the ball. Bend your kicking leg and bring it in front of the ball. Your leg should move over the top of the ball. Then kick your leg backwards, keeping it bent. Hit the centre of the ball with the top of your heel.
There's no need to make this movement particularly big or to lift your knee all the way to hip level as this isn't going to give the shot more power.