The main thing is to give your pet their own cozy corner where they'll feel safe! A bed or house is best placed away from the hustle and bustle, but positioned so the animal can still see the living area and doesn't feel isolated. Food and water bowls should be in a convenient spot, ideally in the kitchen or a well-trafficked part of the apartment, but not right in the walkway where you might step on them. For a cat, a scratching post is absolutely essential - and not just one if you've got a bigger place! Don't skimp on this, or your furniture will definitely suffer.
You need to be more practical with furniture and fabrics. Go for darker upholstery that's more resistant to dirt - suede and light velvet are your enemies! There are some great protective covers out there that save sofas and armchairs. Laminate or tile flooring is better than carpets - way easier to clean up pet hair and any accidents. If you really want that softness underfoot, get a couple of small rugs that are easy to wash.
Don't forget about safety! Hide your cables in cable channels, clear unnecessary stuff off windowsills and shelves that your pet might knock over. For cats, install proper window screens - regular mosquito nets won't hold up. And this is really important - keep all household chemicals away from paws, medicines in a place they can't reach! Regular damp cleaning and vacuuming are your best friends if you don't want your apartment to smell like pet.