This is the audio exerpt of nː spoken within a word. It may sound a little short or unclear, but that's exactly how it's in the real context. For more details, read the below explanation of pronunciation and listen example words that contain nː by pressing the word buttons.
1. Break the airflow by touching the point above the alveolar ridge with the tip of your tongue.
2. Direct the air through your noise instead of the mouth.
3. Relax your vocal cords.
4. Pronounce this sound noticeably longer than normal ones.