Spooky, scary!
You can send out delightfully ominous invites:
Papertastebuds / Via papertastebuds.com
You can have pumpkins double as macabre decor.
$50 from Etsy.
Via etsy.com
Your ring box can really hammer home the point "till death do us part."
$21 from Etsy.
Via etsy.com