When you are getting ready to AP, lie down in a comfortable position, just like you're going to sleep. Calm your brain down, get rid of all your fast moving thoughts, and think of something peaceful. As you drift off to sleeplet yourself slip off to the astral plane. Remember, when you are APing, you are always in control.
You can meet other people on the astral plane, but be careful. People, or animals may not be what they appear to be, and you can bring dark things back wit you.