Hanging ball, presumably you mean a hanging basket that ends up looking ball like when all the plants have grown - if so, wire hanging basket, moss, plant busy lizzie through the mesh every 3/4 gaps depending how big the holes are, patting moss into place round them, adding compost inside the basket as you go. When you've done that, finish off lining the basket with moss, fill up with compost some more and plant in the top as well. You'll need to balance the basket on something like a bucket, without damaging the ones sticking out of the bottom and sides while you finish it.