Recording

Hi, Nelly! Sounds like you're asking about singing without excess tension.

A good approach to reducing tension is to:

First pinpoint what is tensing! Then, either

(1) move those muscles to prevent them from tensing in the first place (i.e.: softening and mobilizing your jaw so it cannot clench, or slowly shaking your head “no” to prevent the neck muscles from “grabbing”) 

OR 

(2) remove those muscles from the equation (ie: preventing tongue tension by singing with the tongue totally relaxed, out of your mouth and resting on your bottom lip). 

The ultimate goal with all of the above is to let the correct muscles do their job without the "help" of those extrinsic muscles that are tensing.

Two things that can help. Try lesson with Camille or any teacher here so you can get one on one feedback. One on one live lessons and feedback is priceless. Also, Go find an open and sing in front of crowd. You can always see how they respond to you.