A very common yoga mudra is the gyaana mudra. The tips of the thumb and index finger form an O and the other three are fingers together, lightly stretched. It signifies the unity of universal and individual consciousness; it symbolizes knowledge. The open hand is the dhyaana mudra, which is usually the mudra for meditation.
Another important pose for meditation is Siddhasana, the sitting asana. It manages to purify the numerous energy channels that exist within our body. when you partially sit on your heel, it touches the perineum. Adding full pressure on the root chakra helps you control your desire.