Every morning I would shoehorn myself onto the train with thousands of expensive-smelling, coiffed women who somehow managed to keep their hair looking great under wool caps in winter and despite hot, stinky gusts of subway backdrafts in the summer. It was an army of ladies sporting fitted waistlines, toned arms, blown-out hair, full faces of makeup and heels (which was incredible, considering all the walking we all had to do). Everyone looked good, no one was phoning it in, and we were all stylish.
I commuted to a job in the city for years, and I wore suits (frankly, they are convenient, and two or three pretty much kept me dressed at work for years), put my feet in flat shoes (or even sneakers or snow boots, and put my cute flat shoes in my bag). I didn't wear a lot of makeup--still don't--and there are days I wear none. Often, my hair isn't blown out, though it looks just fine. When it was longer, I'd pull it back or wear it up. While I have a lot of criticisms about the beauty standard and the ever-changing fashions that are semi-mandatory for women, it's a gross simplification to act like everyone out there is tottering around in six-inch heels with a face of troweled-on makeup.
She decided to go for a year of wearing "modest" clothing--covered her head, wore sleeves, wore skirts that covered her knees, and eschewed makeup and nail polish for the most part. Which, really? This is revolutionary? That's me on a Tuesday (sans head covering, though I have no judgements about head coverings). She gushed about the the men who told her they couldn't take women who were heavily made up seriously (myself, I find it irritating when people who are not held to a standard judge those who are).
Modest dress or not--it's two sides of the same coin. We either judge and shame women for dressing modestly, or we judge and shame women for vanity. In both instances, I have heard people comment that such women are oppressed (by their culture, by beauty standards) that they don't respect or love themselves, that others won't take them seriously because of the way they look.
It's easy to switch one set of standards for another. Dressed up and made-up or modest and plain, they're still standards judging women's appearance. (Though, I do need to add here: I know someone who lived in the UAE, and she was pretty clear that the women there were dressed to the nines under their coverings. And made up, and perfectly coiffed. It's not as simple as folks would have you think.)
My unsolicited advice is this: Dress how you want. Adhere to the dress code at your job, and do so in a way that is comfortable for you (if it won't adversely affect your job). If you don't want to wear makeup, go without if you can. If you want to wear it, wear it. If you're concerned that you're too worried about how you look, go without it for a week. You'll notice that no one goes running and screaming from you. If you want to dress in a way that follows the guidelines or rules of your religion or culture (and you feel safe doing so--unfortunately, there are jerks out there who love to harass women in headscarves), do so. If you prefer your heels and makeup, rock it!
What is modest to one person is slutty to another. What is slutty to one person is modest to another. After awhile, I stopped caring what anyone thought, because I could not win. This isn't a game designed to have any winners for the women assigned as contestants, so I just bowed out, as much as I could.