In order to have the best relationship with a cat, you must treat them as an equal. Your relationship must be altruistic. Their happiness comes first. Cat owners will joke that they are slaves, but in actuality, they love serving their cats, because when a cat sees that you are for them, they are also for you. I wish I could say the same about most humans.
Make some meals with ingredients you can both eat, and invite him/her to the dinner table. I let them eat off my plate, like we are going at the same wild buffalo we just took down. You can also give them their own plate, but always allow them to your plate, so they can see the food is the same as theirs.
You can also toilet train them so they have the option to use the toilet if they so choose, while also providing them with a litterbox. If you travel with your cat, toilet use can come in handy (have some alcohol pads for the toilet seat). Sometimes you can use the garden at the airport, or wherever, but sometimes you can't.
If you have nice furniture, delight in the artistic rendering your cat will add to it. Look at the bigger picture of happiness.