Put tape on the foam to paint straight lines.
(It doesn't really matter what size or shape it is, that's up to you)
Paint two coats of acrylic paint, let dry and remove the tape
Draw and cut a coffin on the cork
Cut the fabric a bit larger than the cork-coffin, enough to be able to fold it over on each side and glue them
Glue the coffin to the foam board.
Finally add the thumb tacks and necklaces!