OP I do get what you mean, some women just always look polished.
Some days I think I manage this, some not, sure it will be less after baby is born !
I was given a book when I was younger by Rachel Zoe, a celeb stylist from America (I hadn't a clue who she was) not my thing but actually had some really good advice in there abut what to invest and what not. Essentially a wardrobe of essentials in black white and caramel can never do you wrong. I have just bought a reasonable (£60) caramel coloured coat and [i think] it looks like it's worth three times that at Least! If it had been black would not have Been the same.
I don't wear make up but do get my lash extensions filled in every other week and wear a light coloured usually nude or taupe nail varnish, it would be rare I'd ever go out with chipped nails. Takes me five minutes to paint them in the morning as I use the quick dry stuff - so probably what most people do on make up. To me that makes me feel polished and 'done' especially in the professional environment.
Hair is my downfall, I'm lazy / don't value time spent poncing about with it. If I could find a quick fix to it always looking good I would do it!
Now I'm a bit too older I spend more on clothes and buy less. Usually Boden sales, joules etc, and feel finally I'm getting it right after quite a few dodgy years.
I personally think the things that make people look polished are well fitting clothes, fairly neutral make up and clothes with a statement something - either jewellery or their hair or a good coat or gilet. I don't really care how others look, you should do what makes you feel good, but for me getting it right makes me feel good especially if I'm in a scenario I could do with a boost.