I cut out a large hole on the back of the box that's roughly in line with the CPU cooler's fan. Then I made another cutout with mounting holes for a 120mm intake fan.

Then cut out those diamond shapes, gently squeezing the tubes and snipping across the fold. Note: The finger joints are diamond-shaped holes cut into the cardboard tubes. The four fingers each ...

They are extremely easy to make, and you just need a cardboard box, some tin foil, scissors, tape and a toothpick. Two holes are cut into the box. One for the pinhole, and one for viewing.

In a pinch, I made this portable easel out of a cardboard box I had saved. It does the trick, ... Keep sharp objects away from little hands, so make sure the cutting is done by an adult. 3.