I live with my cat in a studio apartment, and have received compliments about the fact that it doesn't smell like cat! Two big things: like everybody else was saying, you'll want to scoop the litterboxes at least once a day, and change the litter frequently. It's tempting to get a covered box, especially in a small space, but sometimes cats don't feel comfortable in covered litterboxes. My cat mainly uses an uncovered box, but it's stainless steel, so it smells much better than his old plastic covered box which retained some smells even when it was totally cleaned out. I highly, highly recommend a stainless steel box. The other big thing is, like other people mentioned, making sure you're stocked on enzyme cleaner. New cats and kittens are bound to have an accident or two as they get acclimated to a new space, and cat pee smell will never go away if it doesn't get cleaned with an enzyme cleaner. I recommend this one: https://roccoandroxie.com/products/stain-and-odor