Lay the tapestry flush against the vaulted ceiling. Position the tapestry until you are satisfied with how it looks. For example, you can position the tapestry so that it covers the entire ceiling, so that it is centered on the vaulted ceiling or so that it covers just the top or just the bottom portion of the ceiling.
Smooth out the tapestry. Once the tapestry is in the position in which you want to hang it, smooth it out against the ceiling.
Secure the corners of the tapestry to the ceiling with upholstery tack nails. Gently hammer a tack nail into each of the corners of the tapestry.
Install tack nails into the sides of the tapestry. Gently nail tack nails every 4 to 6 inches along each of the sides of the tapestry to securely affix the decorative element to the vaulted ceiling.