1/ Imagine two strings connecting your shoulders with the ceiling. With your arms completely relaxed, raise both shoulders as high as you can, as if pulled up by the strings. Keep it like that. Now drop your shoulders as if the strings had been cut.
2/ Tense your jaw muscles by clenching your teeth. Keep it like that. Now relax, letting your jaw go completely limp.
3/ Push the tip of your tongue hard against the roof of your mouth. Keep it like that. Now release the tongue, feeling relaxation stream down to the throat.
4/ Push your head back gently as far as it will comfortably go. Keep it like that. Bring it back to its normal position. Now let it fall forward gently, towards your chest. Keep it like that. Bring it back gently and feel the difference.