Touch your tongue tip to the ridge just behind your upper front teeth.
Build up air pressure behind the tongue, then release with a crisp puff. Test it with the paper-flutter trick: the paper should move.
Keep your throat silent; /t/ has no buzz.
After "s" the puff is weaker: compare "top" with "stop".
Now say: tea, sit, top.
✅ Check
Minimal-pair test: say "to" then "do" with a hand on your throat. "to" has a puff and a late buzz; "do" buzzes immediately. If they sound identical, your /t/ needs more air.
⚠️ Common trap
Two traps: no puff at the start, so "to" sounds like "do", and swallowing the final /t/, so "sit" loses its ending. Touch the ridge clearly and let a little air escape.