For this method, I use my tray and mixing up the dye like I would the shaving cream method. However, I make up a huge amount of the dye /shaving cream mixture, pour it into the tray and move the tray to creat soft mixes of the colour. It was a steep learning curve, since the ground wasn't flat and I hadn't worked out what the right dye+ shaving cream+water ratio was best.
It was a windy day too so I couldn't spread out my fabrics flat. Above is my favourite one. Pity it is the smallest piece.