If truth be told, you can meditate in any position.
That's because the peacefulness you find through meditation is always here—whether or not you notice it. It's the ground of life, the source of life, and it really isn't separate from life. So it's available no matter what position you are in.
That said, there are some special positions—and special conditions—that can help you tap into an experience of deep peace more effectively.
For the Basic Minute, sit on an ordinary chair.
Now, plant your legs firmly on the floor or wrap them around the legs of the chair. There's no need to sit in a lotus posture, kneel down or tie yourself in knots. Just avoid dangling one leg over the other, or else your foot might start kicking or your leg might start wiggling without your knowledge or consent.
Now that you are sitting down, sit up. If possible, sit on the edge of the seat without leaning against, or relying on, the back the back of the chair. The main advantage of sitting up this way is that it helps you stay awake and reminds you that the Basic Minute does require some attention. Even though meditation can be very relaxing, it is not a nap.
Your back should be straight so that you are neither dropping down in dejection nor searching upward in hope. You are just here—in a neutral position—open-minded, open-hearted and strong. But make sure you aren't so zealous in keeping your back straight that you become rigid. That would defeat the purpose.
Your head should also be in a neutral position. You might want to imagine that two very kind hands are reaching down, as if from heaven, gently pulling your head upward, lengthening your spine. Think of it this way: For your whole life, gravity has been getting you down—now you need some cosmic traction.
Now, place your hands in any position that is symmetrical. You can clasp them together, rest them on your knees or use any prayer position or yoga position you like. The important thing is that you can hold this position for the full minute so you're not tempted to twiddle.
I recommend you close your eyes for the Basic Minute to minimize distraction. Some people have trouble with this, so it's also okay to keep your eyes open if you prefer. If you do keep your eyes open, just pick a spot on the table or floor in front of you, about 2 feet away, and keep your gaze fixed gently on that spot so your eyes don't wander.
The overall intention is for you to be in a position that is balanced, stable and still. If your body is all over the place—facing this way and that way, doing something that you are not aware of—then your mind would likely to be all over the place too. But if you can place your body in a position that is balanced, stable and still, your mind should get the hint.
As you practice this posture, it will become deeply familiar to you. Pretty soon you will find that you can change your mind significantly just by getting into this posture a little, even for a moment. Just getting into it will remind you of that peacefulness and help you tap into it more quickly.
Then you can be anywhere—on the train, in a meeting, even watching television—and just by subtly adjusting your posture (sitting upright, clasping your hands) you are reminded of your old friend, the Basic Minute...and you experience a moment of peace.