None of us are deciding to be tight and stressed. We get tense, we are tense, and we don't know why. A few common theories we hear are "I must have slept wrong", "I sit all day at the computer", "I was traveling and slept in unfamiliar beds", "My in-laws were in town", " I could come up with a lot more but you recognize some of these, don't you? My experience teaches me something very different and I think we need to reframe tension.
Our unconditioned natural state is fluid, and fluidity is free and responsive and present. The idea of what happened in the past or what will happen in the future has nothing to do with fluidity, which can only be happening in the moment. If sitting at the computer was the reason for tension then as soon as you got up, the tension would stop. As soon as the in-laws left, you'd be relaxed again. Lingering tension goes deeper than a common event.
What we discover in reality is that as soon as the hidden truth of a tension pattern becomes clear to the conscious mind, felt through the body, the tension habit begins to release and resolve, we become more conscious, fluid and free. It's important to work with our conscious/unconscious divide, otherwise the treatment is nothing more than tension maintenance. Tension only resolves in reality, in the present moment of letting go of the theoretical and experiencing the actual.
Try this experiment. Pick up the nearest small object, lift it above your head, then put it back down. Rest back and notice the sensations in your hand, arm, shoulder, the rest of your body... Now, pick up the object, decide you want to lift it over your head but tell yourself that you can't, then put it back down. (just give it a shot) Rest back and notice the sensations in your body... Ok, this exercise isn't perfect because you were aware of lifting the object and then not lifting the object, but maybe you still could feel something different in your body from the two suggestions. Though it depends on how attuned you are with your body sensations and how willingly you did the two suggestions, this exercise is meant to demonstrate the effects of actions that are fully completed and actions that aren't completed. Once there is a desire or urge for action in your system, completion of some sort is needed. Call it satisfaction, which is the opposite of stress, the ahhhh of life.
One last bit. In the examples of theories I gave, two were about sleep and that hunch can actually be really helpful if left open to inquiry. When we sleep, our subconscious urges get to move through the body. When we wake up and narrow back into our trained smaller degree of consciousness, sometimes we can still feel the tension of whatever action was trying to resolve itself during sleep. Meditate in open, kind awareness with the sensation rather than explaining it away as "sleeping wrong" or something like that. You were sleeping right and your system's healing that needs to integrate back into consciousness is right there being felt. Surrender into yourself and find out what's true. Allow your life to expand into the greater consciousness that is always right here and now.
A Strange Feather
All the empty plots,
All the ghosts and fears,
All the grudges and sorrows have
I must have inhaled