The cross polarising techniques is a simple one to create. Just place a polarising filter in front of the lens and photograph a stiff plastic object in front of an LCD computer screen. To illustrate the tip I attached a Hoyarex Linear Polarising filter* to the front of a digital camera. 
I then positioned a plastic cereal container in front of my computer monitor (make sure the background is neutral grey and not a screen saver ) and mounted the camera on a tripod. You can hand hold if there’s enough light to get a camera shake free photo.
When you rotate the polariser you will see a rainbow of colour with the background colour of the monitor.
As you rotate the colours will become stronger and the background will go black.
I repeated the technique using a plastic wine glass
* Any polarising filter can be used – linear or circular . We have a selection for sale here in both screw in and system filters. Polarising filters for sale. The system filters are more practical as you can use one filter with a variety of lenses with different filter threads. Just get the filter, a holder, and a range of adaptor rings for the holder to attach to different lenses.