I will show how to build a Christmas popup card that features a Fractal decomposition of images. You can fit your personal photos and pictures, so that the whole renders as a Christmas tree.
It takes about 1 hour to prepare the card (I did it on PowerPoint, and the file is available if you want to start from something already half-done).
For each card the cutting/folding is about 10 minutes per card. I sent about 12 of them, only one fooled up.
Step 1: The powerpoint template
Step 2: Preparing the pictures
You will need:
2 large pictures
6 medium pictures (half of the large ones size)
18 small pictures (half of the medium ones size)
All the pictures must be squared (use a photo editing program such as GIMP to do so). Resolution is not important, you can keep high-quality photos, but should be at least correct.
Also ensure that all the images fit together: They should share the same darkness level, colors should be pleasing when viewed altogether...
Step 3: Adding the pictures to the ppt file
You can see on the attached screenshot what appears on my Powerpoint: Sorry it is a French version, and it is quite old, but you should find your way out as big boys huh?
Changing the color of a box to an image is clunky on Powerpoint, at least on my version. It may be better on more recent versions.
Step 4: Printing the cards
Now just print it on hard paper, and use a sharp cutter and a ruler and open (cut) all the horizontal borders of the boxes.