This is a very simple 5 min Instructable!
I just watched a post on Hefty.co (video above) showing a guy using scissors and scotch tape to make a hologram viewer device.
The results on video were pretty cool, but...since I live in a FabLab and have acess to a laser cutter I made a template, so you can cut it in acetate without have to mount it with the scotch tape. Ok, It is a little overkill, but...is funnier!
The DXF file attached shows off where you have to cut (red) and just mark it for folding (blue). Use your usual laser power and speed configurations for a thin acetate sheet.
If you don´t have a laser cutter like me, just bring the file to the nearest Fab Lab or makerspace OR you can print the PDF file below and use it as a template to cut the acetate with your good old hands and scissors!
If you browse YouTube for "Hologram Video" you´ll find thousands of examples.