how do you make basic fits look more put together?

i mostly stick to the basic stuff like jeans, plain tops, and neutral colors, because it is easy and comfortable, but sometimes I feel like my outfits end up looking a bit too plain or unfinished. Like it is fine, but not really styled if that makes sense. I don't really want to overhaul my whole wardrobe or start buying a bunch of new clothes, so I am more curious about small tweaks that make a noticeable difference.