I have gotten REALLY creative with my mansion so it doesn't look empty, but usually I'm juggling with the last 3 furniture slots of my house to make things work... as more furnishing is added, I've had to remove tabletop items, leaving lonely tables that were otherwise decorated with food and whatnot.

My basement is also pretty much a bar/sauna place, but I've had to sacrifice ideas like making an extra entertainment or VIP room because there aren't just enough slots... my basement has just 3 big rooms, that's it. Because just trying to partition it properly will take you about 10 slots off... horrible.