There are Different school of Dhyana/Meditation. Also meditation gives full result when practiced under a knowledgeable Guru. The most common Practice is suggested hereunder:
How to Meditate
Meditation increases the ability to concentrate and enhance memory power. It brings in a sense of inner peace and tranquility, and makes you appealing in nature. Meditation is also thought to tap the hidden potentials of an individual.
Difficulty Level: Hard Time Required: 10 - 30 minutes
Find some time out of your daily schedule.
Find a quiet place and sit down.
Be comfortable. Relax.
Keep the face serene. Chin up.
Close your eyes slowly to experience a void darkness. ( Remember to keep your eyelids closed throughout the following steps)
Look into your eyelids as if seeing with your eyelids open.
Keep your mind empty of people, place, things, color or any form.
Try and concentrate on the center of your forehead.
If thoughts arise, bypass them and keep looking with your eyelids closed, going deeper and deeper, leaving form, name, color, and activities far behind you.
Experience the motion of going, as if driving in a car, and you'll be going deeper and deeper - beyond the body and senses.
As you go deeper and deeper with your eyes closed in this dark place, you may see the swirling of smoke-like colours flickering in the darkness and silvery flashes of light.
Look straight in front with your eyelids closed and keep going further and further.
To keep you alert in meditation, take slow deep breaths. Colors will swirl and change pattern rising with each breath.
Keep breathing steady. Let thoughts come and go. You're on a journey going beyond the body and form.
After you feel totally calm and relaxed, gradually open your eyes and spring back to life with renewed energy.
Do not sit for meditation with workload on your mind.
Wear simple, loose clothes, preferably white in color.
If concentrating on 'nothing' seems difficult, try concentrating on your breathing. Another way to concentrate is by uttering the sacred syllable "Om" loudly, which helps arrest your thoughts as it resonates through your body.