Touch the tip or front edge of your tongue to the roof of your mouth just behind your teeth. Keep your jaw relaxed. Stop the air, then release with a puff.

Americans pronounce tieth as tee-uhth (/tiəθ/). It's 4 sounds in 2 syllables. Short, clean, and front-of-mouth — every sound earns its place.
Record yourself saying "tieth" 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.
Don't pronounce the first syllable too fully. The unstressed syllable reduces to a schwa — the lazy "uh" sound — in casual speech.