Keeping your Fridge Cool.
To keep your fridge as cool as possible (especially in summer) you need to keep it as full as possible. If you have spare capacity in your fridge, fill it with fresh water bottles, pop, beer or wine. Each time you open your fridge, it lets cold air out and warm air in, liquid is great at retaining cold so you use less energy and have a colder fridge.
Most people find that turning the fridge up in summer to make it colder actually ends up making it warmer as the fridge itself creates to much heat and because it ends up warmer it uses more gas. Try it yourself on different settings to find which works best for your fridge.
If you have a freezer the same principle applies and don’t let if fill up with ice crystals, speaking of which to defrost the freezer turn it off, empty the contents into a bowl all packed together (keeps the cold in) and use a silicone spatula to help remove the ice inside, never use a sharp or hard implement as it is very easy to pierce you freezer wall or damage a cooling fin and that would be an expensive accident.