The only rule is that there are none
Your home is your own personal space, so make it work for you and your life. This couple, for instance, don't own a TV (their laptop works just fine for them), which gave them more freedom when furnishing their living area. Rather than a traditional sofa, they instead opted for two side-by-side chaise longues to create a cosy space for relaxing. When friends come over, the nearby stools and easy chairs can quickly spring into action.
See the KIVIK series