There is actual science behind it – the Magnus Effect – but learning the skill can be broken down into three clear steps: the run-up, the striking action and the follow-through.
As you approach the ball, place your standing foot (not the one you’re kicking the ball with) next to the ball – about 20cm or so to the side – and point it at a 45° angle to your target (the goal).
The curved movement when you strike the ball should start at the hip. Your hip should be included in the action. This helps create momentum (and power) and spin.