How can I refinish an old piano bench to look shabby chic?

Paint and stress it-- I like light pink and white sanded off and the cover is in a vintage floral fabric or tea stain the fabric for a more shappy chic look. If you like a hint of glamor, use some silver rub-n-buff wax robbed on the decorative edges

Are you asking how to achieve the look?

Buy an Antique-it kit in the hardware.

I would paint the wood base in a white paint and then lightly distress it in the places it would normally wear. Coat with a light colored wax. I would recover the top in whatever color of shabby chic you gravitate towards. Personally I would recover it in a remnant from an old chenille bedspread.

Paint it a soft color and sand a little. Add a ruffle around the bottom attaching it from the underneath side.

That would look awesome if you did that!