banner flags were used to display unit types and ranks as well as clan identification of basic units but where not typically worn into battle. i made mind on the soul purpose for the dress of it.
its very simple to make
get a square Dowel rod cut it at 25% of its length make an angle brace for the corner and glue it together and add a screw going down into the dowel. use a dremmel to cut a grove in the dowel on the inside were you'll attach the banner. paint it the desired color use the dowel rod when assembled to make the template. find a fabric of your choice then get 2" elastic and sew them to your banner. simply staple the elastic in the grooves you made earlier and hot glue them in for a smoother look.