I used some cording I had laying around, but Isabelle used 3/8 inch grograin ribbon.
She also recommend the McDoogle (aka golden arches) straw because it is sturdy and wide enough to thread the grograin through.
I used the tube part of my fabric tube turner which I have misplaced since making the leis, and so the demo shows a drinking straw.
Repeat all the steps until your lei is as long as you want.
To finish, Isabelle (blogless) threads the ends of the grograin ribbin through shells and a
and the wearer ties the ends into a bow to wear. I tied my ends together and the wearer slips the lei over their head. A ribbon bow can be tied on.
Seems to me that this can be done over elastic and made into hair thingies. I'm sure it´s been done:)
Ben Franklin Hawaii has nice instructions for a straw lei with beads.