First off what is the void? Well the void is like an endless universe in your mind. It's like your own personal Matrix. It's a launch pad to the past, present, and future. It's a teleporter to anywhere you wanna go with in your mind and outside of it. Yeah I think that pretty much sums it up.
This technic will train you to enter the void at will. Helping you to Lucid dream and Astral Project.
To start lay down on your back in a quiet comfortable place. Do some streching, wiggle the fingers and toes, open and close your mouth, blink your eyes a few time, and work on anything else that you feel may be tense.
When finished close your eyes and try to lay perfectly still. Take deep but normal breaths until you feel comphy.
Now on an in breath I want you to visualize you are breathing in a glowing white mist. Let this glowing white mist flow up into your crown chakra making it gleam like a bright star and in your mind say "LUCID".
On your out breath imagine the blackness around you growing darker. Feel it wrapping around you. Feel yourself sinking deeply into it. Let all sense of your pychical body go. In your mind say "SLEEP".
Continue doing this; sinking deeper and deeper. When you feel you are reaching a state of sleep I want you to stop. I want you to clear your mind and slowly begin to just let it wonder all on it's own. You may begin to see picture, colors, and hear sounds (this is good you are entering the dreaming and trace state of the void.) Your mind will try to pull you back into consciousness (don't get upset or alarmed) just let it happen and then relax back into the trace state. You want consciousness to kick in! The trick is to train your consciousness to kick in when your are asleep and in the dream state; deep enough in the void that your body will not wake up. How do you know if your deep enough into the void; I'm not sure I can really explain that to you. It's kind of one of those things you just know.
If you can make it to the deep part of the void and stay there; there are a few exit technics that work really well. Often just sitting up will bring you out. The roll method works well. For me I just imagine I'm sitting at the foot of my bed.
Anyway I hope this Technique helps. Good Luck!