Three forms of Astral Projections

I have an interest in Astral travel as Guru Nanak Dev ji once astral travelled with the son of a Haji (Muslim leader)to show him other planets and solar systems with human life on them. This Haji had challenged Guru to prove what he says. Haji himself was scared to go with the Guru when the Guru offered him to come with him and see other planets with life on them, with his own eyes. My muslim friend once told me this story that I hadn't heard from Sikhs. She was surprised that I didn't know this story that is popular among muslims.

Psychic 101 website under training section mentions three forms of projection.

In the first you can look back and see your body. I have had this experience as shown in the picture. I also saw a yellow ball of sun glowing inside the head of the projected body. During this session I had also heard ringing of bells. I had this experience as I was meditating in the Sikh temple when there was no service on.

In the second you will not see the body but be aware of it, and experience some duality. I had this experience when I saw my future, old self taking me to show her house. In this I was aware of body walking behind this old self. I had this experience when I used the vippasana technique of focusing on the air in and around the nostrils.

After reading this I realised that I don't need to worry about astral travel as what I experience during meditation session is astral travel.

In the third form you will no longer be aware of the body. Your experience will be the most vivid only in this form you can project outside the solar system. I agree with the last statement completely. Therefore, don't try to go astral travelling, just try to have a great meditation session. Call upon your guide to help you understand God. Remember, the guide you call upon must be a SatGuru himself, an enlightened one who has seen, known and understood the formless himself. If you don't know of such a guide, just call Guru Nanak or ask the God himself to show you the right path.

Technique on astral projection by Robert Peterson:

Lay down, close your eyes, and relax completely. Imagine that you are separate from the body, and laying inside the body-shell. Imagine that your physical body is vibrating slowly, and your astral body is vibrating at a faster rate. Pretend you can both hear and feel the vibrations throughout your astral body as if you were standing in front of nine-foot speakers. Next, imagine the vibration of the astral body increases in pitch gradually, getting higher and higher. As the pitch gets higher, the two notes go out of sync and a certain resonance gets stronger and stronger.
Repeat this exercise several times. This simple exercise can actually produce the vibrations which can separate you from your body. It also might help to try to listen intently for any sounds "inside" your head at various points in the exercise.