The ground rule is: A stereo picture is not good simply because it is a stereo picture! All rules for taking "flat" pictures apply to stereo pictures in particular. In addition, there are a few more rules:

If your scene includes infinity, the near point should not be nearer then 2.5m when the stereo basis is 65mm and the lens is a standard lens. If this rule of thumb is ignored, the resulting slide will either be hard to mount or completely unusable due to diploplia.

The stereo effect decreases with distance. With a normal stereo base, the ability of the human eye to detect depth disappears at about 60m distance. The three-dimensional effect disappears if the scene is far away. For effective stereo, try to include a smooth progression of objects through the depth of the scene.

The human eye has a limited depth of field. When focused on the foreground, the background automatically will be thrown out of focus. Conversely, when focusing on the background, the foreground will be unsharp. With a stereo picture, everything that is unsharp appears unnatural because everything in the slide is at the same distance (the slide itself) and should, therefore be sharp. So, when taking any picture, the depth of field should be set to ensure that the whole scene is acceptably sharp, usually by using a very small aperture.

Vertical errors and twists between the left and right half of the mounted picture can make images useless. A spirit-level can help to avoid these problems - particularly when using two separate cameras or one camera that is moved between taking each half. A spirit level can also help to avoid a disturbing tilted horizon.

When taking pictures using a slider bar and flash, the flash must not be moved between taking the individual shots to avoid differing shadows.