By the time you turn a quarter of a century old, there are a few beauty products that you should know how to use properly. Don’t get us wrong, we’re not saying you must use them on a daily basis, but there are certain things every girl should know how to do. And plus, these five products will have your skin looking like a million bucks if you use them correctly. We’re talking basics here such as foundation and mascara—not blue eyeshadow and red lipstick. In fact, you’ve probably already got all of these products stashed in your makeup bag, so check out the slideshow above to find out how to use them all properly. It’s for your own good!