How do I focus my thoughts?

How do I keep my mind from getting perturbed from all kinds of thoughts it encounters?

It involves two steps.
* Reflection on thoughts during mediation, as and when needed.
** Focusing those reflected thoughts towards a single thought, peace.

These two steps are so much like an optics setup, where the incoming light is reflected using a reflecting mirror. Since angle of incidence is equal to angle of reflection, therefore by varying the angle at which the mirror is lying with respect to the incident light ray different incident wavelengths can be directed towards the same direction. The second step involves the focusing of all incident rays or broad spectrum light to a single point using a converging lens, like how we focus sunlight to a given point on a paper using a hand lens and notice that it starts burning; confirming the intensity is so high that it starts burning.

Similarly, different thoughts from all possible sources can be reflected towards peace by just meditating as often as needed. All meditation does is, reflects my thoughts and directs me towards peaceful thoughts. Once my random-disturbing thoughts have been reflected towards peace they can be focused at peace by constant remembrance.

Therefore, mediation acts like a reflecting mirror and constant remembrance acts like a hand lens or a converging lens.

This 2 step method is surely makes peaceful any time and each time.