Cover the surface you're going to work on with some newspaper or a plastic tablecloth.
Put inside the blouse a card in order to protect the back of the blouse from paint stains.
Use a plastic surface as place to mix the paint. I used green, white and blue in order to create a water-like print. -Start using one of the dark colour and go lightening it with white, paint small brush strokes to create the "dotted" print.
In the middle of the print mix spots of both main colours in different tones; darker and lighter.
When the creation is done, let it dry.
Once it is dry, iron the blouse so the heat fixes the paint to the fabric.