Second, thread either a cranberry or a piece of popcorn on the tread then double not it. Tip: I suggest using a cranberry since they won't break as easily as popcorn.
Continue to thread a pattern of popcorn and cranberries till you have at least two inches of tread left.
Repeat.
Enjoy!
Tip: Once Christmas season has past you can pull out the string and through the cranberries and popcorn outside for the birds.