I found the video on http://edbdesigns.blogspot.com/
I don't use bandana under my shawl because it feels better without. See my picture below.
You can also tight the both sides of the shawl behind, you can see it in de video and see my pictures below.
You can take one side of the shawl behind and the other side in front of you so you can cover your chest. See my picture below.
I tryed to explain how I wrap my shawl and I hope it's clear and usefull. If you practice you'll learn it quick because it's really easy and doens't take a lot of time (1 or 2 minutes).