Raise the back of your tongue to touch the soft palate (velum). Stop the air, then release.

Americans pronounce cousin as KUH-zuhn (/ˈkʌzən/). Stress falls on the first syllable — keep everything else short and quick. You'll hear it in sentences like "His cousin was busy choosing a dozen roses".
Record yourself saying "cousin" and play it back. The mic stays on your device — nothing's uploaded.
2 syllables, 5 sounds. Tap a syllable to jump to its row, then explore each sound's mouth shape and how it's made.
The textbook way isn't wrong — it's just not how anyone actually says it.
In "cousin", the short unstressed vowel before "n" disappears — the schwa is absorbed and the "n" becomes the syllable nucleus on its own. Schwa is absorbed — consonant becomes the syllable nucleus.
Stress falls on the first syllable, not the others. Stretch KUH — keep everything else short and quick.
Don't pronounce the first syllable too fully. The unstressed syllable reduces to a schwa — the lazy "uh" sound — in casual speech.