Clean the cap.

Screw it to the board you want to use. Get it lined up just the way you want it. Don't be afraid to use shims under the cap or to trim the cap a bit with a grinder if necessary.

Then cover the cap with cotton batting. Lay velvet cloth over the cotton batting and trim it around the cap and antler bases carefully with a scissors to fit the outside edge of the cap.

Use a glue gun and glue the velvet down the board aroud the outside edge of the cap and around the antler bases.

Then cover the edges of the velvet with piping like you can find in a fabric store.

Here's shot of one I did for a buck I shot a long time ago.

http://i8.photobucket.com/albums/a21...kyshots161.jpg