1. 虚灵顶劲 (Xū Líng Dǐng Jìn) – Clear, Quickly Effective, Crown of Head, Energetic Power

   The mind should be clear, alert, and naturally at ease. Do not use physical exertion, which would stiffen the neck and constrict the flow of qi and blood. Instead, use your inner energetic power to effortlessly press the head and neck upward (it feels like the top of the head is being pulled up by an attached string). Without this, the dynamic vital spirit cannot rise.

2. 含胸拔背 (Hán Xiōng Bá Bèi) – Contain Chest, Stretch Back

   Keep the chest slightly contained to allow the qi to sink into the dantian. The back should be slightly stretched, enabling the spine to straighten and the body's structure to stabilize. This allows the body to remain balanced and rooted, with the potential for movement to originate from the back.

3. 松腰 (Sōng Yāo) – Relax the Waist

   The waist is the commander of the body; relaxing it allows the entire body to stay grounded and centered. This relaxation facilitates the transfer of energy from the legs to the upper body, ensuring smooth and connected movements.

4. 分虚实 (Fēn Xū Shí) – Distinguish Between Full and Empty

   Understanding the distinction between full (substantial) and empty (insubstantial) is critical to maintaining balance and fluidity in movement. This differentiation allows for the efficient transfer of energy and avoids clumsiness or stiffness in the transitions.

5. 沉肩坠肘 (Chén Jiān Zhuì Zhǒu) – Sink Shoulders, Drop Elbows

   The shoulders should be relaxed and allowed to sink naturally, while the elbows drop downward. This prevents the energy from rising incorrectly, which could create tension or block the flow of qi. Relaxing the shoulders and elbows ensures that the power is directed effectively.

6. 用意不用力 (Yòng Yì Bù Yòng Lì) – Use Mind, Not Force

   Taijiquan emphasizes the use of mental focus rather than brute force. By guiding the body's movements with the mind's intent, one can move smoothly and effectively. This principle allows for internal energy (qi) to flow naturally, rather than being blocked by physical tension.

7. 上下相随 (Shàng Xià Xiāng Suí) – Upper and Lower Coordinate

   The movements of the upper and lower parts of the body should be synchronized and harmonious. When the upper body moves, the lower body should follow, and vice versa. This coordination ensures that the entire body moves as one unit, allowing for a seamless flow of energy.

8. 内外相合 (Nèi Wài Xiāng Hé) – Inner and Outer Harmonize

   The external movements should be in harmony with the internal energy. When the body moves, the mind should guide it, and the energy should follow. This inner-outer unity is essential for the power to manifest in a controlled and effective manner.

9. 相连不断 (Xiāng Lián Bù Duàn) – Continuity Without Interruption

   The movements in Taijiquan should be continuous and without breaks. Each posture flows into the next in a seamless manner, creating a constant, unbroken stream of energy. This continuity allows for the effective circulation of qi throughout the body.

10. 动中求静 (Dòng Zhōng Qiú Jìng) – Seek Stillness in Movement

Even within movement, there should be a sense of calm and stillness. This mental quietness allows the practitioner to remain centered and balanced, with the mind guiding the body effortlessly. Finding stillness in motion is key to mastering the art of Taijiquan.

Biography from Wikipedia.com

Yang Chengfu 杨澄甫 (1883–1936) was born into the famous Yang family of taijiquan practitioners, the son of Yang Jianhou and grandson of Yang Luchan. With his older brother Yang Shaohou and colleagues Wu Jianquan and Sun Lutang, he was among the first teachers to offer tai chi instruction to the general public at the Beijing Physical Culture Research Institute from 1914 until 1928. He moved to Shanghai in 1928.

Chengfu is known for having "smoothed" out the somewhat more vigorous training routine he learned from his family as well as emphasising a "large frame" (大架; dà jià) with expansive movements in stepping and using large circular motions with the arms. His smooth, evenly paced large frame form and its hundreds of offshoots has been the standard for Yang-style taijiquan (and overwhelmingly in the public imagination for taijiquan in general) ever since.

Chengfu is the official author of two books on the style, Application Methods of Tai Chi, published in 1931, and Essence and Applications of Tai Chi, published in 1934. His second book was translated into English in 2005.