Listen to the way people talk to one another and use those conversations and patterns in your dialogue to make it sound authentic. You'll notice that people talk differently when they're with different people, so make sure that you include that when you're writing dialogue.  Disregard parts of the conversation that will not translate well when written down. For example, every "hello" and "goodbye" does not need to be written. Some of your dialogue might start with a "Did you do 'this'?" or "Why did you do 'this'?" Keep a notebook to record small pieces of real-world dialogue that stand out to you. To get a good feel for the balance that you need in your dialogue between realistic speech and book speech you need to read good dialogue in books and in movies. Look at books and scripts and see what works and what doesn't and try to figure out why.  Look for writers whose dialogue rings true to your ear, regardless of what other readers or critics may say. If you need a starting point, you might check out the work of Douglas Adams, Toni Morrison, and Judy Blume, who are known for their realistic, layered, and vivid dialogue. Checking out and practicing writing dialogue for screenplays and radio plays is really useful in developing dialogue, since those are both very dependent on dialogue. Douglas Adams, from the above writers, got his start writing radio plays, which is one reason for his fantastic dialogue. You will need to completely understand your characters before you can make them talk. You'll need to know things like whether they're taciturn and monosyllabic, or whether they love to use lots of big words to impress people, and so on.  You don't need to write every character detail into your work, but you should know them yourself. Things like age, gender, education level, region where they're from, tone of voice, will all make a difference in how a character talks. For example, a poor American teen girl is going to talk very differently from a rich, old, British guy. Give each character a distinct voice....

How would you rephrase that briefly using Vietnamese?
Chú ý vào cuộc hội thoại thực tế. Đọc hội thoại hay. Phát triển nhân vật toàn diện. Tránh dùng lời thoại hoa mỹ.