First, read the English article below.

Stand in front of your mirror at home and practice smiling. It might feel a little silly to do, but if you want your pictures to look a certain way, you’ll need to figure out how to create your most attractive, natural smile in advance. Take a few practice selfies, too. Looking at an actual photo of yourself can really help you figure out what adjustments to make. School pictures are usually taken straight-on, but very subtle changes in your head positioning can make a big difference. When you practice smiling in the mirror or in selfies, test out slightly different head positions to find out which one makes your facial features look best.  If possible, avoid cheesy poses such as resting your head on your fist.  Make sure you sit or stand up straight when your picture is taken. If you’re a good listener, you’ll get a much better photo. The photographer is a professional, so do your best to do as they say. Listen and respect the photographer just like you would any other adult. To avoid having a fake or forced smile, make sure to think about something that makes you happy while your picture is taken. Consider thinking about playing with your dog or eating your favorite food. 

Now, please write a short abstract for it in Vietnamese. Abstract:
Tập cười. Thử chụp ở vài góc độ và chọn một góc chụp. Nghe lời thợ chụp ảnh. Nghĩ về những chuyện vui.