Use a mirror to see your tongue when you say the "th" sound.
Put the tip of your tongue between your top and bottom front teeth. Blow out air.
The "th" sounds in English can be voiced and unvoiced (with vibration or without vibration). In this pair we are practicing the unvoiced "th" sound.
Touch the tip of your tongue to the back of your upper teeth then drop your tongue and blow out air.
The "th" sound
The "th" sound
The "t" sound
The "t" sound