Flare your lips and lift the mid-front tongue close to the roof of your mouth. Blow air through without voicing.

Americans pronounce shiny as SHAHY-nee (/ˈʃaɪni/). Stress falls on the first syllable — keep everything else short and quick. You'll hear it in sentences like "She showed the shiny shoe to the shop".
Record yourself saying "shiny" 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 SHAHY — keep everything else short and quick.