This Bully Beef can opener dates back to the First World War when soldiers fighting in the trenches in France would have used the device to open tins of food. It's a hard-wearing object and is ...

Start by taking a full tin can. Using a tin opener, begin removing the lid, but stop when the lid is just over halfway off. Carefully bend the lid out using a knife and empty the contents.

This could include: Non-perishable food that doesn’t need cooking, such as ready-to-eat tinned meat, fruit or vegetables (and a tin opener). As with water, how much you need will vary based on ...