Learn to "taste" useless thoughts. Our present level of consciousness gives itself a sense of being useful by entertaining an endless stream of useless thoughts. The more identified we are with those useless thoughts, the more we become a captive of that very consciousness. The task is to learn to "taste" thoughts so that we can discern their usefulness. The first part of the exercise is to be as present as you can to the thoughts that appear, and inwardly ask yourself: What does this thought actually feel/taste like? What is moving through me when I identify and give myself over to this thought? For the second part of the exercise, go for a short walk or choose a task that you have to do, and as best you can for the period of time that you have your attention, try to sense completely your environment, both outwardly and inwardly, as a whole. With practice we can begin to be present enough to recognize whether what we are tasting and experiencing is useful or useless. Then we can understand that useless thoughts are only useful to something that we don't want to be a part of.