As was explored in "Deep Frying 101: How to Achieve Crispy Golden Perfection," different fats and oils have different smoke points, which change their usefulness for deep-frying foods. However, oil is used for more than just deep frying, and understanding their flavors and reactions to heat is an important part of making good cooking substitutions across the board. Here are a few more tips and tricks to using oil that might be useful in your kitchen!
What are smoke points? The "smoke point" of an oil is the temperature at which it breaks down and (as the name suggests) starts smoking. Despite the visual similarities of different oils, there are a lot of variants between them which cause them to react to heat differently. There are even differences between oils of the same category, such as extra virgin olive oil versus light olive oil, so be aware of that.
Deep-Frying Oils Most oils with high-smoking points are going to work for deep-frying; these include canola oil, corn oil, extra light olive oil, and safflower oil. If you want an oil that will actually imbue your deep-fried goods with some of its flavor, you could try peanut oil too. The best oil to use is probably canola oil, as it's the most versatile, neutral type that can be used in almost every type of cooking.
Flavorful Cooking Oils If you're not working with high temperatures and you're using the oil to impart flavor on your food, olive oil is a great option. Extra virgin olive oil is one of the most popular because of its delicate flavor and aroma, but there are dozens of other varieties of flavored olive oil that are worth trying too. Outside of olive oils, peanut oil, sunflower oil, and soybean oil are solid options.
Baking Oils and Fats The best oils and fats to use in baking are butter, vegetable shortening, lard, vegetable oil, and canola oil. These will imbue your cakes and other baked goods with the right sweetness and texture. As mentioned in "Emergency Ingredient Substitutions for Baking" it's better to stick to recommended substitutions since even minor changes can throw off the underlying chemistry of the dish.