How do we pronounce 'th' sound /ð/ and /θ/?

This video talks about pronouncing 'th' sound /ð/ and /θ/.

SCOLAR releases a series of eight three-minute TV episodes to raise the awareness of proper English pronunciation among the general public, in particular, our students and the workforce. The episodes illustrate, in fun and entertaining ways, various common mispronunciation among some people in Hong Kong in daily life situations.

The episode list is here.