An A4 size felt sheet
embroidery thread and needle
The size of the holder totally depends on how big you want it to be and if you want to use it for holding things other than business cards. I cut an 8-inch long piece keeping the width of the A4 size sheet.
Now fold that in half and cut.
Further cut one of the halves in two and trim down a bit and make an arch so it's easy to pull out cards.
Blanket stitch the two halves onto the full piece..
PS. I used polyester felt instead of wool felt and the holder won't stay shut. So I need to work on a clasp to do that. Pics when that happens...