soften edge of beach/city section and join the photos
new layer: fill with purple. set layer to multiply
new layer: gradient map. mask out beach
cut out horse , man and wings of bird.
Make planet/moon....circle cut out piece of beach...use soft brush to erase half of moon... duplicate layer -transform top layer clock wise to create correct shadow shape ,, layer blend mode to colour burn...
create stars using soft brush..
create rainbow. gradient transparent rainbow.. warp to shape
horse/wings and man layers set to layer blend mode. >lum'y