I'm one of those players who adapt or expand their style of playing as I go along. The longer I played with my main household, the more DLCs I added. For the longest time, my Sims didn't have a family. Then, after playing with that household for about half a year, I decided it was time to add on to the gameplay. So they had their first kid, and when I discovered I actually liked the family gameplay, I started adding the corresponding DLCs.
I mostly buy DLCs for the worlds and new gameplay, and I try to mix them up a bit, too. For example, my main household lives in Brindleton Bay. The mom is a scientist, so I get to use Get to Work, while the dad is in the military, so I make use of the Strangerville pack. They started out in Strangerville, too, before moving to Del Sol Valley. They are both spellcasters, too, mostly because I want them to have familiars so Grim doesn't reap them 😁 All of their five kids have either already graduated High School or are about to, then it's off to college. The oldest daughter has a degree in physics and lives in a penthouse in San Myshuno, her sister has an arts degree and owns a nice cottage with an artist's workshop in Windenburg. Their brother is about to become a marine biologist and will live in Henford-on-Bagley. Not sure about the twins, but I think the girl will either be an influencer or interior designer, and since she loves horses, I'll get her a ranch in Chestnut Ridge. And there are some features I use for pretty much every household, like writing a will or a bucket list, and I love the customised dates.
Since I'm also a rotational player, I have households in different worlds. One's in San Sequoia, one in Evergreen Harbour, then I have one in Ravenwood, there's one in Moonwood Mill... and with each household, I try to use the gameplay the respective DLC and world offers. Sometimes I create a new household when a new pack comes out to put every single aspect of the gameplay to the test without messing up existing households.