A lot of people, when trying them for the first time on snow, just throw their head back. Good way to land upside down.
With skis on the flip comes from your hips and thighs... throw them up and forwards, follow the curve up your body then through your shoulders and head. You'll be around 270 degrees before you know what even happened.
And don't throw it too early and clip your head on the lip, seen that a few times