Mindfulness is the simplest, and there's not much to getting started. Try it now.

Take five to fifteen minutes. Focus your attention on, and notice your breathing. You will immediately become distracted. Notice thoughts as they arise, and attempt to return your attention to your breathing. Repeat as necessary or desired.

The subjective experience of this loop changes the more practice you get. You haven't failed if you can't reach a steady-state. You're already in steady-state of yourselfness.

I've found that meditation has also helped me. I read several books on the subject of meditation but found "The Mind Illuminated" to be the best.