Or acknowledge it, write it down if it's an actionable to-do, then let it go. It probably won't return, and you'll have a great list of things that were previously buzzing around in your head, taking up space now down on paper in front of you.

You're not meditating if you stop to write it down.

There is no single right way to meditate. My dad has been practicing Nichiren Buddhism for over 30 years and he taught me this. He chants twice daily with a gohanzen, sometimes writing, sometimes only reciting text.

Immediately made me think of this: http://www.theonion.com/article/ayahuasca-shaman-dreading-an...

This, and if you need further justification, think of this like any other skill. By practicing the act of intense (and nonjudgmental) focus, over time, your ability to focus intently will improve. In choosing to focus on something internal, you decouple this practice from any particular external context or environment, and any improvement you achieve will be applicable to the broadest range of tasks. In calmly accepting (and dismissing) any intrusive thoughts or feelings, you likewise improve your ability to remain calm in the face of unintended internal or external distractions, decreasing your stress levels (along with any of their negative health implications). Go into it without any expectations (as you might then stress if you fail to meet them), for the most benefit. Nothing else required, just the intentional and unimpeded practice of a particular skill.

I have been using Muse (no affiliation) which has a headband that measures brain signals, for me, it seems like it is able to tell when my mind has wandered off thinking about life's minutia, when I am supposed to be concentrating on breathing. It gives the feedback by stirring up the sound of waves and wind and really tries to get you back on track. This is my prompt to let go and recommit to focusing on my breathing and then the waves and winds will calm down again.

Not sure if this works, but I was using those sound entrainment binaural beats for theta deep sleep waves, or set to meditation. There's some free frequency generators online or app store. You should try it with your headband to see if there are increases in frequency of the binaural beat frequency you've chosen in app

That sounds really neat. I will give it a try.

I used to count the number of [slow deep] breathes I take to remove all thoughts. Once you master that you can stop counting and clear your mind.