You can vary the width of the strip by adding or removing a fold. Below an example for a narrower strip (folding both sides towards the middle for a second time, starting from picture six)
Fold one end over..
and then the other.
fold one side over to exactly the middle
repeat the same with the other side.
Do the same thing again, fold one side to the middle
and repeat with the other side.
now fold one side on to the other. It leaves you with a narrow strip..