Round your lips into a tight circle. Lift the back of your tongue toward the soft palate and add voice.

Americans pronounce welcoming as WEHL-kuh-muhng (/ˈwɛlkəməŋ/). The L in "welcoming" is a dark L — the back of the tongue rises toward the soft palate, adding a small "uh" quality before the L. This is called the Dark L vs Light L, a hallmark of natural-sounding American speech. It comes out as WEHL·kuh·muhng. Stress falls on the first syllable — keep everything else short and quick. You'll hear it in sentences like "The server was very welcoming".
Record yourself saying "welcoming" 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.
Round your lips into a tight circle. Lift the back of your tongue toward the soft palate and add voice.

Drop your jaw moderately. Touch the tongue tip behind the bottom front teeth and lift the mid-front part slightly toward the roof.

Keep the tongue tip down and pull the back of the tongue up toward the throat. The 'dark' sound comes from the back.

The schwa before M disappears — M becomes the vowel of the syllable. Go straight from the previous consonant to M.

Relax your lips, jaw, and tongue completely. Drop your jaw slightly and keep the tongue neutral.
Lift the back of your tongue to the soft palate. Lower your soft palate to let air flow through your nose.

The textbook way isn't wrong — it's just not how anyone actually says it.
The L in "welcoming" is a dark L — the back of the tongue rises toward the soft palate, adding a small "uh" quality before the L. Dark L adds a small schwa-like "uh" before the L. The back of the tongue lifts toward the soft palate.
Stress falls on the first syllable, not the others. Stretch WEHL — 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.