These ingredients will add excess oil to your skin and make oily skin worse. Read the ingredients listed on the moisturizer packaging before you buy. Look for moisturizers labeled oil-free and that contain dimethicone rather than petroleum. Moisturizers that contain dimethicone will help create a matte effect while petroleum containing moisturizers may make your skin oilier. No matter what moisturizer you choose, make sure that the packaging says that it is non-comedogenic or non-acnegenic. Moisturizers that are labeled non-comedogenic or non-acnegenic contain ingredients that are less likely to cause pimples. Apply a thin layer of moisturizer at first and then decide if you need more. Only dispense a chickpea size amount onto your fingertips and only add more if your face still seems dry after applying it. Just because a particular moisturizer works well for someone else with oily skin does not mean that it will work the same for you.  If a friend recommends a product or you read rave reviews about a moisturizer, try to get a sample before you buy it. Makeup counters in department stores often provide samples of their products if you ask nicely.

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Write a summary of the previous text in Vietnamese:
Tránh dùng sản phẩm dưỡng ẩm có chứa dầu như mỡ khoáng hoặc bơ cây hạt mỡ. Chọn sản phẩm dưỡng ẩm có chứa dimethicone. Chọn sản phẩm dưỡng ẩm không gây bí da hoặc không gây mụn. Dùng ít sản phẩm dưỡng ẩm. Thử nhiều loại sản phẩm dưỡng ẩm đến khi bạn tìm được loại phù hợp.