Take no thought for the morrow. We as human beings and as students of the upper path have to eventually come to realize where it is that our life is being spent consuming the empty calories of thought. There's no substance in thought that can satisfy the soul whose heart hungers for what is true.
We must work to see the futility of listening to an unconscious nature -- a mind that is a conditioned instrument of all that came before it. This mind is always looking outside of itself in order to know and to save itself. The mind can only rely on imagination, and imagination is the ultimate addiction.
In any unwanted moment, work to be an observer of thought, of what's talking to you. The real observer stays out of what is observed because it doesn't need to think about what it's observing... because it IS what it's observing.
Don't judge what you are seeing. Use what you see to remember yourself; your true Self. You can't stop yourself from going in and out of the present moment. But the more that you are able to see that you come and go, the more something remains in place that's aware of that relationship that belongs to this level of life. And the remembrance of yourself belongs to an entirely different level of yourself.