Here are some tips to help you.
1 - Bites lower lip (nervous, when lying).
2 - Self-consciously covers mouth before answering questions.
3 - Voice pitch goes higher, the voice is more negative, less fluid.
4 - Blink rate increases (sign of nervousness).
5 - A lot of throat clearing.
6 - Makes vague, sweeping statements
7 - Voice pitch goes higher, the voice is more negative, less fluid
TO BE CONTINUED. more tips are coming.