To start you need a pin back. You can find these at the craft store by the bag full. I happened to pick-up some self adhesive ones on sale; you don't need them to be, but it is helpful for little hands to wrap the fabric when there's some cushion and stick.
Take strips of scrap fabric or ribbon and start wrapping the pin.
After wrapping the fabric, attach the wire to one end (right above the clasp) and finish with a simple loop so that you don't leave a scratchy end.
Now, wrap once, add one bead - repeat. When you get to the end attach the wire by wrapping it tightly above the clasp, clip off extra wire and end with another simple loop.
It ends up looking something like this.
There are many ways to fool around with the basic idea...call it a snow day Medal of Bravery.