Playing qin is pretty much related to practicing Taichi (or Taijiquan). Here I attempted to translate the 10 principles of practicing Taichi to English. The Chinese part was taken from Zhengzi Taichiquan.
Many concept are not easy to translate due to my limited English skill. If anyone has better idea, please let me know. I'll be very appreciate it.
一、虛靈頂勁：頂勁者，頭容正直，神貫於頂也。不可用力，用力則項強血氣不能流通，須有虛靈自然之意。非有虛靈頂勁，則精神不能提
1, Xū líng dǐng jìn : "Xu" means empty, humble, void or abstract, the opposite of solid, or concrete. "Ling" means spirit. "Ding Jin" means that the head is upright, so the spirit goes to the top. However, don't use force. Using force, the neck will become stiff and the blood circulation won't be smooth. Keep the idea of emptiness and nature. If there is no emptiness, then the spirit and energy cannot be raised.
二、含胸拔背：含胸者，胸略內涵，使氣沉於丹田也。胸忌挺出，挺出則氣擁於胸際，上重下輕，腳根易於浮起。拔背者，氣貼於背也。能含胸則自能拔背，能拔背則力能由背發，所向無敵也。
2, Hánxiōng bá bèi : Han Xiong means that the chest is a little bit sunk in, in order to let the energy go down to the Dantian. Make sure that the chest is not elongated and standing out. If the chest is elongated and out, the qi energy will all stay in the chest area, and that will cause a heavier top and lighter bottom, and the heels will become unstable. While the back should be a little bit pulled, in order to enable the force energy to come out from the back to protect the whole body to be invincible.
三、鬆腰：腰為一身主宰，能鬆腰後兩足有力，下盤穩固。虛實變化，皆由腰動。故曰命意源頭在腰際，有不得力，必於腰腿求之也。
3, Sōng yāo, loosen waist: Our waist dominates the whole body. If one can loosen the waist, then the two legs become stronger, and the lower part of the body becomes stable. All the changes of abstract and concrete are ruled by the action of the waist. Therefore, the source of energy is at the waist. If there is no effective energy, one must be pursued from the waist and legs.
四、分虛實：太極拳以分虛實為第一義。如全身皆坐在右腿，則右腿為實，左腿為虛。全身坐在左腿，則左腿為實，右腿為虛。虛實能分，而後轉動輕靈，毫不用力。如不能分，則邁步重滯，自立不穩， 而易為人所牽動。
4, Fēn xūshí, distinguish the "abstract (emptiness)" and "concrete (solidness)": The most important principle of Taichiquan is the distinguishing of abstract and concrete. If the weight is on the right leg, then the right leg is the concrete one and the left leg is the abstract one, and vice versa. After distinguishing the abstract and concrete, then the movement will become more easy without using any force. If one cannot distinguish the abstract and concrete, the steps will become heavy and stagnant, and standing will become unstable and easy to be pushed by others.
五、沉肩墜肘：沉肩者，肩鬆開下垂也。若不能鬆垂，兩肩端起，則氣亦隨之而上，全身皆不得力矣。墜肘者，肘往下鬆墜之意。肘若懸起，則肩不能沉，放人不遠，近於外家拳之斷勁矣。
5, Chén Jiān Zhuì Zhǒu, drop shoulders and elbows: Shoulders should be relaxed and sagging, otherwise the shoulders will be shrugging, and the qi energy will follow the shoulder up, which will cause the whole body not to have efficient energy. While the elbows are also dropped, so shoulders won't shrug. This way the energy won't be easily broken by outside force.
六、用意不用力：太極拳論所云，全是用意不用力。練太極拳，全身鬆開，不使有絲毫之拙力以留滯於筋骨血脈之間，以自束縛，然後能輕靈變化，圓轉自如。或疑不用力，何以能長力？蓋人身之有經絡，如地之有溝洫。溝恤不塞而水行，筋絡不閉而氣通。如渾身僵勁充滿經絡，氣血停滯，轉動不靈，牽一髮而全身動矣。若不用力而用意，意之所屆，氣即至焉。如是氣血流注，日日貫輸，周流全身，無時停滯，長久練習，則其真正內勁，即太極拳論中所云，極柔軟然後能極堅剛也。太極拳功夫純熟之人，臂膊如棉裹鐵，分量極沉。練外家拳者，用力則顯有力，不用力時則甚輕浮，可見其力乃外勁浮面之勁也。外家拳之力最易引動，不足尚也。
6, Yòngyì bùyòng lì, using mind but not using force: All the theory that Taijiquan talks about is on the idea of using the mind but not using the force. Practicing Taijiquan, the whole body has to be loose, in order not to let any clumsy energy stay in between blood and vessels, muscles and bones to constrain oneself. Then one can move easily and freely. When there is no energy blockage, then the mind can guide the qi energy to wherever the intention is. After much practicing, blood and qi energy flows through the whole body without blockage, and one can gain the real inner force. As Taijiquan theory often says that after the extreme soft, is the extreme power. When you see a master of Taijiquan, his or her arms are like iron covered with cotton, full of inner force.
七、上下相隨：上下相隨者，即太極拳論中所云，其根在腳，發於腿，主宰於腰，形於手指，由腳而腿而腰，總須完整一氣也。手動腰動足動，眼神亦隨之動，如是方可謂上下相隨，有一不動，即散亂也。
7, shàngxià xiāng suí, up and down coordinate with each other: The root is at the feet, developed to the legs, ruled by the waist, formed to the fingers, all that has to achieve as a whole. Hand moves, waist moves, feet moves, and the eyes also follow the movement, then it is said the up and down are coordinated with each other. If there is one part not following the movement, that is scattered.
八、內外相合：太極所練在神，故云神為主帥，身為軀使。精袖能提得起自然舉動輕靈。架子不外虛實開合。所謂開者，不但手足開，心意亦與之俱開；所謂合者，不但手足合，心意亦與之俱合：能內外合為一氣，則渾然無間矣。
8, Nèiwài xianghé, inside and outside matched: Taiji practicing is focused on the spirit (or mind), so it is called that the spirit is the master, and the body is driven by the master. The forms are basically no more than "opening" and "combining", "abstract" and "concrete". "Open" means not only the hands and legs are open, but the mind is open as well. "Combine" means not only the hands and legs are coordinated, the mind is also merged. Inside and outside are as a whole, without any space in between.
九、相連不斷：外家拳術，其勁乃後天之拙勁，故有起有止，有續有斷。舊力已斷，新力未生地時，最易為人所乘。太極拳用意不用力，自始至終，綿綿不斷，周而復始，循環無窮，原論所謂，如長江大河滔滔不絕。又曰，運勁如抽絲，皆言其貫串一氣也。
9, Xiānglián bùduàn, continuous connection without any break: If the force has any break, the old force cannot connect to the new force, that is the weakest time to let outside force to take advantage. Taijiquan does not use force but mind, from the beginning to the end, continuous, round and round, endless cycle. Just like the endless flow in the Long River. It is also like pulling a silk thread, which all mean the continuous energy.
十、動中求靜動靜合一：外家拳以跳擲為能，用盡氣力，故練習之後，無不氣喘者。太極拳以靜制動，雖動猶靜。故練架子愈慢愈好，慢者呼吸深長。氣沉丹田，自無血脈僨張 之弊。學者細心體會，庶可得其意焉。
10, Dòng zhōng qiú jìng dòngjìng hé yī, While moving, seeking the stillness; the moving and the stillness are as one: Too much jumping up and down will use too much energy. Taijiquan is using the stillness to control the moving energy. The slower the better for practicing all movements. When it is slow, the breath will be long. The qi energy will sink to the Dantian, therefore there will be no problem caused by sudden excitement. The learner should carefully experience it, then one can understand the essential meaning.
