Google Cardboard has become pretty popular, but I find the cardboard box rather awkward to use and have a suggestion to old older technology in the form of a Stereoscope to make the viewing process much more enjoyable.
Step 1: Get the Parts You Need:
You will need the following:
1. A Smartphone [ But you would have needed this anyhow if you were using Google Cardboard ]
2. A Smarthone Holder [ I am using an Otterbox holder but any holder will work ]
3. A piece of Aluminium that you can bend L shaped to attach the holder to the viewer bar
4. A few small Bolts and Nuts to hold everything together
Step 2: Positioning the Smartphone As the Correct Distance
Remember the following:
1. The Lenses in every Stereoscope is different and thus you will have to find the best distance to place the phone from the lenses.
2. Stereoscopes have sliding picture holders, but they aren't really good for holding phones [ See picture ]
3. I suggest you look through the viewer and move one hand back and forth to find the position you eyes focus best.
4. Now drill the holes for the L shaped bracket and place the phone at the distance determined in step 3.
Step 3: You Are Done - Now Run Google Cardboard App
That is it, now you just have to run the Google Cardboard App and Enjoy