While meditation requires some trial and error, the benefits of practicing arrive long belong mastery does. From Waking Up: A Guide to Spirituality Without Religion.
How to Meditate
1. Sit comfortably, with your spine erect, either in a chair or cross-legged on a cushion.
2. Close your eyes, take a few deep breaths, and feel the points of contact between your body and the chair or the floor. Notice the sensations associated with sitting— feelings of pressure, warmth, tingling, vibration, etc.
3. Gradually become aware of the process of breathing. Pay attention to wherever you feel the breath most distinctly—either at your nostrils or in the rising and falling of your abdomen.
4. Allow your attention to rest in the mere sensation of breathing. (You don’t have to control your breath. Just let it come and go naturally.)
5. Every time your mind wanders in thought, gently return it to the breath.
6. As you focus on the process of breathing, you will also perceive sounds, bodily sensations, or emotions. Simply observe these phenomena as they appear in consciousness and then return to the breath.
7. The moment you notice that you have been lost in thought, observe the present thought itself as an object of consciousness. Then return your attention to the breath— or to any sounds or sensations arising in the next moment.
8. Continue in this way until you can merely witness all objects of consciousness—sights, sounds, sensations, emotions, even thoughts themselves—as they arise, change, and pass away.
Those who are new to this practice generally find it useful to hear instructions of this kind spoken aloud during the course of a meditation session. I have posted guided meditations of varying length on my website.