Recently, I have found myself giving basic sitting meditation instruction to small groups of people on several occasions. Although I am not any kind of "official" Dharma teacher, as a practitioner I am sometimes asked to explain to people just what it is we do when we're on that cushion. I thought I would jot it all down here in case someone might find it useful.
First, find a comfortable sitting position. Traditionally, we sit on the floor using a cushion and a mat. If you have these items, great! If not, don't be discouraged. Folded blankets or towels and firm pillows are perfectly fine if you have them. And if you don't have them, or if you can't sit on the floor because of injury, illness, joint pain or just plain age, no worries! Sitting in a chair is also perfectly fine.
The main thing is to sit so that you can remain comfortable with your back straight and vertical. If sitting on the floor/cushion, aim to keep your knees lower than your hips, either kneeling or in one of the variations of the lotus or crossed-legs positions. This tilts the hips forward slightly, allowing the back to line up naturally in the correct position. (These positions can be challenging to many westerners, so don't be discouraged if you find it difficult at first. Just be patient and gentle with yourself. You'll get it.)
If you sit in a chair, the knees-below-the-hips thing still applies. You might find it helpful to use a thin pillow to raise you up an inch or two. But the most important thing is don't lean back in the chair! This leads to sleepiness (not to mention a stiff back). Whichever way you sit, keep your back straight up and down. Imagine the vertebrae are like a stack of quarters.
There. That's the hard part. It's all downhill from here, kids!
Hands: there are lots of things to do with the hands. In Zen, we use the "Cosmic Mudra," right palm facing up in the lap, left hand facing up on top of it, thumbs touching lightly to form a soft oval.
This is a traditional hand position, but there's nothing magic about it. Try it. If it works for you, great. If not, try another way. You can rest your hands facing upwards on your thighs, thumb and index finger touching lightly. Or you can simply rest your palms downward on your knees. Just pick one way and stick with it.
Eyes: open or closed? I have tried it both ways. When mine are closed, I tend to fall asleep, and since I'm pretty good at falling asleep anyway, I find eyes open works better for me. Again, the Zen way is to let your eyes droop to half-mast, and let your gaze rest on a spot on the floor a couple feet away from you. Do what makes sense for you.
If you've gotten this far, congratulations! You're meditating!
But what to do with the mind? That's a subject for next time. Hit me with any questions or comments you may have. Remember, I'm not an infallible authority, so don't take anything on my say-so.