Find the subject for your photograph. It must be a stationary object, if you wish to use a portrait the subject must remain absolutely still or it will not work.
Place your camera on a sturdy surface or tripod. Do not try to hold the camera; any motion at all will cause the image not to work for a stereogram.
Make sure the subject/object is centered in the image. You will have to reference this center point for a second picture to create the stereogram, so make sure you know where the center of the photo is.
Take the photograph.
Move the camera left or right no more than about 2-1/2 inches. Note which direction you've moved the camera. If you move to the right, this will become the image for the right eye. If you move to the left, this will become the image for the left eye. It is also important to center this second photograph on the same spot the first photograph was centered on.
Transfer the images to an image editing program on your computer.
Place both images on one page next to each other. Make sure you have the left photograph on the left side of the page and the right photograph on the right side of the page.
Save the image and print it (landscape format works best) full page.
Restrict the view from each eye seeing the image on the opposite side. The right eye must only see the right image and the left eye the left image. You can try using an empty paper towel roll cut in two, one for each eye, or two toilet paper rolls like binoculars, to restrict the view of each eye.
Adjust the distance from the photographs to your eye by moving closer or further away to focus the images into a converged 3D image.