My characters all have storylines. I cheat skills/money, whatever I need to, to stick with the storyline so that it's not just a grind of keeping needs up.
I have 3 families, all living in Sulani and good friends with each other. BUt I give them real stories and that's the trick.
I have my mixed family detective couple. She had 3 kids she adopted before meeting him, and he had 6 with his ex. wife, 3 which he took to live with him (and his ex has custody of the other three). He gets along with all his kids and the ones living with his ex. come visit him on a regular basis but his kids don't like their bio mum.. they tolerate her and visit once in awhie but mostlly they don't.
Then there's my stay at home dad and writer mum family with 9 kids and (currently) two foster kids. They've had 5 bio kids, and adopted 4, some from foster care. The mum dreamed of being an archaelogist but dropped out of school to have a family. She's never regretted it, but passed on her love of archaelogy to the oldest daughter on a "Welcome to teenagerhood" trip to the jungle. That oldest just finished her history degree and has been to the jungle several more times and that's where she met her husband. One of their other children, (adopted son, 3rd oldest child age wise) is married to the one of the oldest from the previous family now and together they are taking after their parents in raising a big adopted family.
And then there's China and Erwin (the one premade I play). Best friends from childhood, China moved to sulani (where she met the other families and became friends) and Erwin came to crash on her couch after hearing rumous of mermaids, cuz he's always loved a good conspiracy! (He never found them, I don't play occults). Eventually they fell in love and they have 3 kids, Itzel and Knox are teens and Gigi is a child. China is a conservationist and working hard to clean up the island (they just revamped their house to be eco-friendly with the new pack)
All the families lives are entwined in some ways, and, like I said, I just cheat money/needs cuz I don't want to play a grinding game, I want to tell a story. I do'nt want my Sim to have to leave the jungle when I'm not done with my story there, cuz she can't afford another vacation day, or whatever. Each member of the family has their own interests/personality.. I decorate their rooms and homes accordingly, I take time with them to establish friendships, backsgtories etc etc. etc.