You cut the fabric into small pieces, a bit bigger than a postage stamp, put dollops of glue on the backs with a small brush, and stick them randomly to the object, mixing the colours up. You can overlap the edges.
You don't need a flat surface to work on, you can scrunch the fabric up to fit the curves of a bottle. Then you add some bits of decoration, braid, pompoms, ribbon, beads, or any other trimmings out of your bit box. The glue takes a long time to dry, and you need lashings of it because it soaks into the fabric.