Preheating the oven for at least 15 minutes before placing your food item into it is a prerequisite. By doing so, your food will cook more evenly and will not require warming up time which may spoil the softness of the food.
If your circulating fan has an on/off switch, then make sure that it has been turned to the "on" position.
Preparing and Baking the Recipe
Check out your food recipe and prepare it per the instructions given. Once your recipe is prepared, you will have to adjust the cooking time by rotating the knob or pressing the button, whichever is available on the convection oven.
Keep in mind that if the recipe you are preparing is for a conventional oven, you will have to set the time to at least 25 percent less in a convection oven. Instead of cooking the food for 25 percent less time, you can also set the temperature of your convection oven for less than what is required in a conventional oven.
Checking the Baked Food
Once your convection oven has finished its cooking, it is a good idea to take out the recipe and check if it has been cooked properly and evenly or not. If you are baking a dense cake, you may need to set the same time as in a conventional oven, but at a lower temperature.
If your cake’s top is dry and hard, try to lower the temperature even further the next time. If you are baking small cookies, set the temperature the same as in a conventional oven, but decrease the time.
Convection Bake Settings
Some convection ovens have "convection bake" settings for cakes, muffins and cookies. If you are cooking them on a single rack, it is best to decrease the oven's temperature by 20 to 25 degrees Fahrenheit.
Convection Roast Settings
If your convection oven has "convection roast" settings for poultry and meat, set the temperature the same as in a conventional oven for 15 minutes, and decrease it by 25 degrees Fahrenheit for the rest of the roast.
Convection Broil Settings
Some convection ovens also have "convection broil" settings for broiling your food. If you are using this option, you will have to apply the same time and temperature as in a conventional oven.