Iron your cover in
half and place your passport inside. Fold the edges over, tucking each
end over the front and back cover. Pin down both ends. I’d recommend
closing and opening your passport with the cover on a few times here to
make sure there’s enough room for the passport to close all the way.
Take your passport out and press both ends with an iron, and then sew
the flaps down. I sewed all along the top and bottom of the cover. This
will also sew the seam shut from the turning.