These pins are simply a sturdy base around a circular hole large enough to get a scarf or bundle of hair pressed into so a stick can be inserted behind or through, holding it in place. And for that, all you need is a small stack of clay sheets, and a cutter for the hole to get you started. How you decorate the surface of the clay is then wide open for you. Create a stick to match by wrapping clay around a skewer or a very stiff bit of wire and apply a similar surface treatment.
Cat Szetu just loved making pins like this one here. I say this in the past tense because I have not been able to find recent work of hers online. Perhaps she is really busy making pins. But I do like this example because the surface is decorated in a rather straightforward manner, with slivers of clay cut from a Skinner blended sheet, curling around the surface. That gradation of color and the smooth curving lines create a quiet and calm type of visual movement that, together, keeps the simple layering of clay from feeling stale.
Cat has plenty more pieces to jumpstart your own ideas. Just go to her Flickr photostream and scroll around.