I'm quite fortunate that I look younger than my age. I'm in my fifties but relatively wrinkle-free, and my foundation hides the few that I have.
So I tend to see myself as a woman of that younger age - somewhere in my forties. I dress, style my hair and do my makeup appropriately to that age. I don't go for the dolled-up look or the "mutton dressed as lamb" look because it is usually my aim to blend in and pass by unnoticed.