Starting a save file - build progress

since im in the process of starting to make families to fill up the places I built I've been wondering. How many places should I fill up? Because realistically I know that EA worlds are empty for the benefit of the player, but I want my save to be more lively. How many houses/apartments in the save should I leave empty for the people who would download it?

and even then I'm undecided about how to deal with those empty apartments/houses. I will still get the basic stuff in, so it looks like a place you would move into, so like full kitchen/bathroom, but I don't know how much should I fill/leave empty.