Any tips on how to stick with a legacy?

I'm fed up of constantly making new sims, decorating houses then playing a few hours with the sim only to get bored. How can I stay motivated to stick with the same sim, family and legacy? I don't even start a new family in the same world, I just always click new game instead lol. I even tried making social media accounts to share my family progress but I'm already slacking there haha! Any tips would be greatly appreciated aha!