Tapestrys! You can get a huge one for cheap, and hang it on the wall. Its a nice way to cover a wall with something pretty and is a fraction the cost of most other wall decorations of the same size.

Also one thing i like to do is just make anything into decorations. Like just find stuff and make it decoration. Garage sales, craigslist, and buying stuff that isn’t meant to be decoration to use it as such. One time i bought a pack of post cards with oil painting art on them, and hung them up all next to eachother on the wall in a grid. Was only like 8$ and i got a ton of them.