This is the audio exerpt of d 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 d by pressing the word buttons.
1. Break the airflow by touching the point above the alveolar ridge with the tip of your tongue.
2. Follow the interruption with a sudden and audible release of the air.
3. Vibrate your vocal cords.