I'm unable to find a drill to make holes in the test plastic sheets. I have been projecting images onto snow, and snow-covered bushes... with little success.
It is crucial for the surface to be smooth and that it faces the projector flat for an actual presentation of the image - which now seems too obvious - but there were interesting effects.
I've managed to create a possible screen to-be also. I've been thinking of various material to use as the screen, such as plastic, mist, smoke, to achieve the desired atmosphere.
I'll look into ways of controlling mist and smoke tomorrow. Then plastic sheets, once I drill holes in them.