These suggestions are for Halloween since that is the most relevant holiday at the moment. I will surely have some ideas for Christmas too, but I'm hoping these might be seen in time to make an appearance.
*Trees! Can we please have some stand alone, gnarly, leafless or autumn trees? There are just really not enough for any season, in either RS or BS....
*Witch decor! We've got costumes, and some zombie decor, and lots and lots of spiders and webs. But witches, basically a Halloween icon, are no where to be found! I would really love a witch to stir our recent cauldrons, as well as witchy decor like crystal balls, brooms, and maybe a black silhouette flying in the sky. Spell books, specimen jars, crows, and a black cat would all be welcome. Maybe some tables and chairs and other decor in green/purple/black for a nice departure from orange/black. Can we have a smoky spell fire/cauldron?! I understand that you have to leave some room for the following year's ideas, but witches, and ghosts, could really use some fleshing out. Which leads me to...
*Ghosts! We have a little bit of haunted stuff, but I would love a ghost floor decoration, even if it's the "in a sheet" kind. A tree with the little ones you tie on? A glowing graveyard ghost!
*Wall decor: I would love some picture frames with ghosts in them, or people with black/red eyes and fangs, or monsters. Web covered specimen/book shelves, large wall cobwebs, and some festive garlands.
* I would love some creepy lanterns for floor decor, some autumn columns of some kind, and a large black candelabra! Clusters of melted candles, either free standing or on a table.
*I am not a fan of actual dead people decor at all, but we could definitely use some bones!
*Werewolves! Pretty pleeeeease I would love one creeping around my graveyard.