Time for another tutorial I think.
To begin, get a paperback book that you wish to upcycle and remove the cover from the front, back and spine and line the spine of the book to face yourself. It’s also worth manipulating the spine to make it easier for it to meet itself when it’s finished.
From the left hand side (what is the top of the book) take the corner and fold at a 90°degree angle, to meet the spine of the book.
Next, take the newly folded edge and fold again so that the flat edge meets the spine again.
Repeat these two folds throughout every page of the book and you will begin to see the birdcage shape take form.