1) Spoon 2 tablespoons yoghurt into each mould. Freeze for 1 hour or until firm.
2) Pour 2 tablespoons juice into each mould. Freeze for 1 hour or until just firm.
3) Meanwhile, process watermelon until smooth. Pour 2 tablespoons watermelon into each mould. Place lids in position or press a paddle-pop stick in the centre of each mould. Freeze overnight or until frozen.
4) To remove from moulds, run under warm water for 3 seconds. Serve.