Mindfulness of Thoughts
Begin by setting a timer for ten mines.
Sit with your back straight but not rigid - as if there's a string pulling you gently up from the top of your head.
You may close your eyes, or if that's not comfortable, you may keep your eyes open and maintain a soft gaze focused on the floor a couple of feet in front of you.
Beginning by noticing the points of contact between your body and the chair, feeling the warmth and pressure.
Gently moving your attention to the sensations of breathing. For a few breaths, experience the body inhaling and exhaling.
When a thought comes to mind, simply notice that it is there and tag or name it. The tag does not have to be precise and may be something like "remembering", "worrying", judging", "planning", "fantasizing", "conversing" for those conversations you have in your mind, and the general category of "thinking". the naming should be light and is not the most important thing. More important is the noticing that your mind has wandered and getting some space from the thoughts by naming or tagging them.
There is no need to follow the thought, either arguing with or agreeing with it. No need to even complete the thought. Just guide your attention back to the breath until the next thought arises. Of course, it's quite likely that the next thought will follow on the heals of the current thought. That's perfectly natural and as you continue to practice you will find that the mind quiets down.