I'm 'Dr' at work. Except, I'm not really, as clients and colleagues all use my first name, I'm only 'Dr' on important bits of paper.
At home, I never use my title with my married name, at the kids' schools, for anything medical related (last thing I want is a doctor assuming medical knowledge I don't have!) or on flight bookings (ditto airline staff).
I just randomly used my title when ordering a compost bin, and it actually felt quite nice (if a bit odd). I am (with Dr Biden) of the view that, if you've earned it, you have a right to use it whenever you damn well want. Maybe I'm missing a trick and should use it more in daily life.