I'm 33 and have the exact opposite problem, and have been ID'd precisely twice in my life. One at an 18th where they were ID'ing everyone and one where the assistant obviously was having a bad day as she was trying to ID me for Schloer! I'm hoping I'm going to give the opposite end of the spectrum that might give you some ideas.
Clothing wise I gravitate towards a more formal style generally. Lots of tailored dresses, trousers rather than jeans, blouses and floaty tops. Skirts and dresses are worn with tights. Even in jeans I tend to pair with boots, maybe a boatneck top with a jacket.
You'll find 3 pairs of trainers in amongst my shoe collection. One pair masquerades as a ballet pump in flesh tones, one pair are black and are actually steel toe caps and the last are a pair of Nike's from around 2003! The rest of my shoes are primarily court shoes, from kitten to platform with a few ballet flats thrown in for good measure.
Make up - I've always been a make up fiend. I do wear a full face daily. I stick with more neutral shades during the day but never just one flat shade. Mascara is a must, and I float about with eyeliner and just using shadow to line the eye. Blusher and/or bronzer depending on season and usually a deeper coloured lipstick. If I wear coloured nail polish it is one colour all over no art and nails are never extremely long.
9 times out of 10 my hair is up either in a claw clip, bun or fancy pony. It is rather long (sits below my waist line).
Finally I think, my handbag probably ages me more than anything! I like a medium size multi pocketed organizer and I live out of it! Pens, tissues, medicines, plasters, books, hand sanitiser, keys etc.
Colour wise for clothes and accessories I tend towards black and red with a few blues, greys and pinks thrown in. I also have quite a number of scarves (floaty and woollen), jewellery is simple unless I'm going out (smaller studs in ears, perhaps pearl necklace, just my wedding/engagement/eternity rings and a watch). I guess even my choice of phone cover isn't "young" - it's a Van Gogh!
I was essentially born middle aged. I can't think of anything else to add right now :)