I love clouds and skies, and when you multiply them and twist them you can create really interesting images.
Since I know what the objects are the title is pretty obvious. A church spire, or a terraced house roof floating in the sky can look very spooky though. Odd edges to the original photos create little details floating above or to the side of the main object. The best photos to use are mainly sky with the foliage or building in one corner.
The cloud scapes also help give atmosphere (pun intended) to the pictures.
I did consider making these black and white but I think the colours help.