Berries are the fruit we get the most questions about. They are picked ripe, which is why they taste so good, but it also means they have a short life once they reach your kitchen.
The first rule is simple: do not wash them until you are about to eat them. Water sitting on the skin is what makes a strawberry go soft and mouldy. Tip the punnet onto a plate, throw away any berry that is already bruised, and put the rest back in a container lined with kitchen paper.
Second, give them air. A sealed box traps moisture; a container with the lid slightly open, or the original ventilated punnet, lets the berries breathe. Keep them in the main part of the fridge rather than the crisper drawer, which is often too humid.
Finally, if you know you will not finish the pack, freeze it on the day it arrives. Hull the strawberries, spread them on a tray so they do not stick together, and bag them once frozen. They will not be good for eating whole again, but they make the best smoothies and compotes all winter long.