If you’re the type of busy cook who often leaves their food in the oven for too long, use the timer built into the appliance to alert you when the cycle has finished. Some electronics have built in timers that stop the cooking after a period of time. Always check the manual.

Conventional ovens cook from the top and bottom, and often have functions to allow them to be used as a grill. Fan assisted ovens (sometimes called 4D cooking by some manufacturers) uses top and bottom elements with a fan element at the rear. The fan motor pushes are around the enclosure for even cooking. Conventional cooking is for baking and help cakes to rise. Fan assisted cooking is for meat, poultry and a majority of other cooking. 

Some ovens combine these uses and they can be selected with a function selector switch. Always read the manual.

Oven manuals by manufacturers such as Hotpoint (Beko Europe), AEG (Electrolux) and Bosch often contain a matrix to show you how long certain food items should be cooked for. Always keep an eye on your cooking.

This depends how often you use your machine. For daily use, it’s recommended to check once a month. If you have childen you may have to check more often if you forget to check their pockets before washing trousers!