You can go into meditation just by sitting, but then be just sitting; do not do anything else. If you can be just sitting, it becomes meditation. Be completely in the sitting; nonmovement should be your only movement. In fact, the word Zen comes from the word zazen, which means, just sitting, doing nothing. If you can just sit, doing nothing with your body and nothing with your mind, it becomes meditation; but it is difficult.
You can sit very easily when you are doing something else but the moment you are just sitting and doing nothing, it becomes a problem. Every fibre of the body begins to move inside; every vein, every muscle, begins to move. You will begin to feel a subtle trembling; you will be aware of many points in the body of which you have never been aware of before. And the more you try to just sit, the more movement you will feel inside you. So sitting can be used only if you have done other things first.
You can just walk, that is easier. You can just dance, that is even easier. And after you have been doing other things that are easier, then you can sit. Sitting in a buddha posture is the last thing to do really; it should never be done in the beginning. Only after you have begun to feel identified totally with movement can you begin to feel totally identified with nonmovement.