Sims 4 Household Ideas?!

Try doing the "average family" kind of thing. It's actually really fun because if you have the Parenthood pack it's actually super interesting. If you don't want to do that, you should try doing different aspiraations, traits, jobs, etc. I'm actually having trouble with making different households, and I'm getting bored as well. The Sims 3 is also fun, so you could take a break from the Sims 4 (if that's hwat you're playing). I hope this helped! :)

Have you ever tried the Random Legacy Challenge? Even if you don't play challenges the family rolls help a lot to give some variety to your households, one time you can get a married couple with adopted and natural children and another time a single parent with five kids with different partners xD if you also use the rest of the rolls it can make some pretty good stories

This is how I would create unique families:
Roll the dice for number of family members.
Roll the dice for each member's age + gender
For each family member, I would use a trait generator.
Based on the results, I would start to have a picture in my mind what the family looks like.