My current game started with 3 separate households. Some made in CAS others were gallery finds. The only thing they have in common is a bit of a backstory. I play each household for a week.
I find that having a backstory gives me something to use as a jumping off point or a direction to take.
For example, one of the households was a ya Hispanic gay male and his elderly mother. His father was never in the picture, so growing up he had to work at the same business where his mother was employed. There was never much money, but he did learn about business from the owner of the company. He is in the business career and is ambitious and looking for love. He wants to marry and adopt children, he wants a big family, a family unlike the one he grew up in.