Press your lips together, add vocal cord vibration, then release.

Americans pronounce booming as BOO-muhng (/ˈbuməŋ/). Stress falls on the first syllable — keep everything else short and quick. You'll hear it in sentences like "The bread and butter business is booming".
Record yourself saying "booming" 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.
Stress falls on the first syllable, not the others. Stretch BOO — 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.