I laid the scarf flat with the tassles on either sides.
I then placed the bolster at the top of the scarf and roll the fabric around.
I cut a length of jute string to fasten the ends and achieve the industrial/army vibe my boy was after (see my guide to decorating a kid's room here and my post for a no-zip cushion here). You could use a silk scarf and some ribbon for a boudoir look.