I took a really interesting class, tutored by Wilma Sharp. It was a Kaleidoscope technique class and included the Perspex templates (4 different sizes) and a hinged mirror to help you with placement of the template on your images. You need to have the image printed a number of times and the same number of images printed in reverse.
We were provided the images too and Wilma chose a generic photo of a tea cup and saucer. Each layout in the class came out quite different depending on where participants had placed their template.
This was my initial layout:
We completed it with enough time to have a second go (Bless You Wilma for providing so many extras) so I chose to do a different size (therefore using a different number of photos) and this is how it turned out: