what should i get for my room?

my mum is buying a lot of stuff for my room but i dont really know what i should buy. i already have 3 posters and a fair amount of ornaments, i do kind of want more posters and ornaments but surely that isnt all you put in a room. what else should i put in here

for context my room has 3 frankenstein posters, a few drawings and a haunted masquerade mask on the wall, a shitton of figures on my cabinet, a bunch of books in my closet, nothing else. should i make a special interest shrine? should i make myself an ornament? who knows