Dress for my shape rather than fashion, even if it means a style that I love passing me by.
Less make up, more focus on skincare, as PP said. In fact a general "less is more"
Accessorizing - spending a bit more on nicer quality and more versatile accessories (eg decent watch with leather strap, leather bag etc).
Likewise, spending more on real leather shoes, sandals and boots that will last, rather than cheap flimsy fashion shoes.
Regular hair cut and colour.
For me, these changes come with having slightly more disposable income these days so less need to buy cheaper end fast-fashion.
I often think about my SIL, who is much younger and far more attractive than me, but covers herself in make up, fake eyelashes and nails, clip on hair extensions, cheap super-fashionable clothes. I think she would look even better if she just put in a bit less effort.