I'm no interior designer, but I think it's fun to let decor mutate slowly instead of "redoing the living room". If I see a chair I like, what do I need to chan

I'm no interior designer, but I think it's fun to let decor mutate slowly instead of "redoing the living room". If I see a chair I like, what do I need to change for it to fit in with what I have? I don't know if it's cheaper in the long run, but it does keep things more interesting imo.