LOW TECH: (easy & low cost)

Materials: aluminum foil, black felt marker, pin, opaque tape, piece of cardboard.

1) Flatten a 1 inch square of aluminum foil on a piece of cardboard.

2) Blacken foil on side with the black marker

3) Gently make a hole in the center of the foil with the pin [small cactus needle?]

4) Remove lens from camera

5) Carefully tape pinhole over camera, black side towards camera

taping a pinhole over the front of a 35mm camera

If you have a camera with an automatic exposure, then you can begin taking pictures immadiately.
You will not be able to "see" the image in the view finder, too dark. Have fun!