Before you enjoy the feast (this is South Indian food btw)

First wash your hands

Use your right hand and right hand only! (left hand is for another dedicated purpose in daily life)

Practise this: use your index and middle fingers to hold food, then use the other fingers to tear a piece off

Should fold and dip in sauce

You can do the same thing to tear off a part of a dosa

Shape it like a container to grab some of the fillings in the middle. Enjoy!