Besides harai goshi there are numerous other hip throw variations which i wont go into individually. However all these throws follow the same base mechanics with minor differences.

To start i set the throw by turning away from my opponent and planting my outside foot as far back as possible. My arms should be ready to wheel throw my opponent.
From here the movement starts at the bottom and works up:
-I use my legs to push off the ground and spring my opponent upwards.
-My hips and lower torso arch towards the ground for leverage.
-And my arms and upper torso rotate my opponent over my hips.