I am p and r and over 40 I shop at charity shops in posh rural towns and eBay.
Clean hair in a pony tail and a fresh natural outdoorsy look, so little to no make up, just sun screen.
Gilets with jeans or slim fitted shirts, always merino or cashmere ( charity shops).
You absolutely must be slim and fit so take up country sports, walking, running, anything, there is no substitute for the benefit of fresh air on skin and general well being being surrounded by animals of all description large and small. Definitely no packaged, processed foods, plenty of fresh veg.
Check out the fashion geared towards the country sport/ equestrian genre such as Joules. Beautiful fabrics, timeless classics and easy to wear.
You will ooze confidence and be happy in yourself being outdoors close to nature and animals and wearing things that are comfy and practical.
You don't need to bother with the urban preoccupation and expense of nails, hair cuts etc if you are outdoorsy, fresh looking , slim, strong and fit.