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

Americans pronounce cowboy as KOW-boy (/ˈkaʊˌbɔɪ/). Stress falls on the first syllable — keep everything else short and quick.
Record yourself saying "cowboy" and play it back. The mic stays on your device — nothing's uploaded.
2 syllables, 4 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.
Stress falls on the first syllable, not the others. Stretch KOW — keep everything else short and quick.