This is a step-by-step of an instructable I made a week ago.
Step 1: The Base.
Then put layers of clear tape, sticky side up, onto the loop. This should make a base of clear tape 1cm wider on each side than you want your pouch to be.
Step 2: The Middle.
Make sure there isn't any gaps.
Step 3: Folding.
Now take it off the masking tape loop.
You now need to trimm the entire thing so there isn't any sticky or rough edges.
You can use these pouches for lots of things and they cost nearly nothing.