Bring small luggage straps to attach to your handlebar bag and Carradice bag so that they are easier to carry around grocery stores, bus/train stations, on hikes, etc.
I spent 3 months in Australia with my handlebar bag tucked under my arm every time I left the bicycle for anything. It was uncomfortable and awkward to carry around like that. This year I clipped a luggage strap to the rings on the sides of my handlebar bag, and I can carry it over my shoulder quite comfortably.