***Sorry, I’m not good with words so I’ve also included the pictures to help make sense of what I’m saying.
I started from the end of the phone book and folded my way forward. Start with an unfolded page.
Fold the top right corner over to meet the binding. Make sure the bottom right vertex gets folded through.
Fold the bottom right corner over to meet the binding. I tried to make sure that this corner landed the same distance up from the bottom of the page, as the distance the last corner landed down from the top of the page.
After you fold the first page it can be used as a template for the rest (that’s why I started from the back).