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

Americans pronounce composes as kuhm-POH-zuhz (/kəmˈpoʊzəz/). Stress falls on the second syllable — keep everything else short and quick. You'll hear it in sentences like "He writes his own lyrics and composes the melody on his guitar".
Record yourself saying "composes" and play it back. The mic stays on your device — nothing's uploaded.
3 syllables, 8 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 second syllable, not the others. Stretch POH — 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.