My sister started buying art & decorative stuff almost immediately after getting a new house. My mother bought some stuff for her as well-- like some pillow covers for decorative pillows on the couch. My sister loves black cats so my mother got her some pillows with zoomed in pictures of black cat faces. She sent us a picture of her eldest black cat (she has 3 of them) sitting on the couch next to the pillows. She also purchased some artwork for the walls. Got a 3-piece Star Wars thing to go above the couch, and I think the one above her bed will be a waterfall or something.
I used to collect stuff to put on shelves-- all sorts of knickknacks, mugs, shot glasses, mini lion statues, etc. But, my cats are a-holes so most of them got broken or had to be put away. My furniture is gloss black with gold accents so I grabbed a couple of black & gold framed mirrors from Dollar Tree to hang on some nails that were on the walls (so I didn't keep hurting my hand by putting my hand on the wall in the dark & not remembering where the nails were). I also have a cool black and gold clock with clear plastic between the edge and the middle so it looks like the face is floating. I've got a blue and gold sun and moon hanging thing from Indonesia, although it has lost a couple of pieces over the years. One of these days I'll get around to taking pictures and posting them. I used to have a "fandelier"-- I made a little chandelier out of clear plastic beads to go around the bulb on my ceiling fan bc the globe broke. It looked cool until my brother hit it while playing with one of my swords & broke it (the fandelier, not the sword). I think I end up buying more decor items for my friend's house than for my own. LOL. I got my friend an Optimus Prime hologram type wall art thing that he keeps in a prominent spot in his room.