Sit in a comfortable position and relax with your eyes closed for a few moments.
Now just observe your thoughts creeping into your consciousness, each one clamoring for attention -- daily events, emotional problems, future desires, etc.
Now imagine you are in a completely dark room with a large picture window covered by a black blind.
There is no pattern to the blind.
It is just black.
Concentrate now on that blind without allowing any distracting thoughts to intrude.
If they do, push them back out of the way.
Simply continue to concentrate on the black blind.
When you can hold an expression of complete blankness for just a short time, you will begin to have a different perspective, where time and distance take on a new meaning.
Continued practice gives you better and better control over the sundry idle thoughts constantly trying to invade your consciousness.
When you can control your thoughts during your daily life, you're one giant step further on your ladder of progressive development.
If it helps, imagine that you are a yogi or a lama that already has this power heightened to a fine tuned degree.