I feel good in my mid-40s. I work with a lot of young people, which I think helps me feel young, I can wear what I want to work, so I can experiment, and in a creative environment, anything goes.
I've just had my hair dyed grey (from brown - but my re-growth has got very grey-white lately, and I'm fed up of trying to keep it hidden), and the young 'uns love it. I need to wear a little make-up every day, and almost always wear lipstick now (shout out for Maybelline Superstay which goes NOWHERE).
I exercise regularly, although am slightly heavier than I'd like to be - I've spent a lifetime of easily controlled weight by doing nothing, so this has been a bit tricky for me to get my head around, but it is what it is.
Most important is attitude I think, I don't care so much about what other people think, I just do and wear what I want. I'm confident in my decisions. In terms of invisibility, although attractive enough, I've never been a head-turner, so I can't say I miss that. But equally DH and I are happy, so I'm not really looking for people to notice me either (except him of course. And seeing as he didn't notice my fairly radical change of hair colour, perhaps I have actually become invisible lol).
Be kind to yourself, accept yourself. You don't need to be perfect, but equally, there's nothing wrong with striving to be better.