Fold the bottom edge up (appx. 4 1/2") to form the pocket size/shape and crease it.
Fold the top down and crease it, as well, forming the flap.
Trim off any excess length from the flap and round the corners.
Open the paper up and cut slits along the creases on the long edges.
Go ahead and cut off the top pieces of the long edges attached to the packet's flap.
You now have 4 edge pieces where you will be glueing to form and complete the packet.
Technically, you can cut off the bottom edge pieces just like you cut off the top ones, but we left them and glued them down to give the finished packet added support/stability.
Fold the bottom back up along the crease you previously created.
Fold the edges around to create a pocket and glue them down.