Article in English: To start exercising your cheek muscles, make a face as though you just ate a lemon or something remarkably sour. Your lips should be in a slight pucker or pout and your cheeks should be partially sucked in. Your teeth should not be clenched together, as this can prevent you from sucking your cheeks in, but your lips do need to be closed.   Note - this method is a folk remedy. In other words, it's not supported by any sort of scientific evidence, but rather by vague, unverifiable, anecdotal evidence. Thus, it is not guaranteed to work.  Your cheeks should naturally indent inward, with the deepest part of the indentation resting in between your top and bottom teeth, roughly halfway between the front and back of your mouth. Try eating or drinking something sour if you have a hard time imagining the appropriate facial expression - your natural reaction to sourness is what this exercise is imitating. Locate the areas on your cheeks where the indentations are the deepest. Gently hold this spot down on both cheeks using both index fingers. Keep your fingers firmly fixed to these spots as you prepare to move your mouth. You can also hold these spots with your thumb or the rounded end of a pencil if you find it easier. Gradually ease your expression into a wide grin, keeping your fingers fixed to the same spots on your face. Your smile should be wide and open-mouthed, as natural dimples generally appear when someone has a fairly wide smile. Your fingers should now be positioned near the corners of your smile, where dimples would naturally occur if you had them.  Check your appearance in a mirror. If the location of your fingertips seems slightly off, you may need to slightly slide your fingertips across your cheeks to the proper location. Press your desired dimple area firmly with your fingertips or with the rounded end of a pencil. For temporary dimples, release immediately. Take a picture, if desired. Note that these dimples will disappear as soon as you relax your mouth. To train your cheeks into forming more...

Summary in Vietnamese:
Chúm môi lại và hóp má vào. Ấn và giữ điểm lõm. Mỉm cười và chỉnh lại vị trí ngón tay nếu cần thiết. Tiếp tục ấn 30 phút nữa, hoặc lâu hơn. Lặp lại hàng ngày.