You have already practice the most common and universal mudra, anjail, the prayer position of hands in front of your heart. Since this mudra is so accessible it is a great mudra to start with. You can also practice the classic yoga meditation mudra of chin or jnana mudra, with the index finger touching the thumb. When practicing a mudra bring all of your attention and focus to your hands. The hands should be active and firm but not tense. Try to feel the prana, life force energy, activated by the mudra.