Many foods keep fresh for longer when kept cold.
When shopping: make sure that fresh and frozen food is not exposed to room temperature for longer than absolutely necessary.
On the move: carry fresh food in a insulated bag to keep it cool.
At home: stock the fridge correctly, according to the different temperature zones, to make sure that food keeps fresh for longer. Put products with a shorter expiry date at the front where you can see them, and use them first.