This is a photo taken during a private lesson I had a few years ago with Grandmaster Chen Xiaowang. I like to look over some of the notes I've taken over the years. It's hard to retain everything you're told during a martial arts lesson, so I try to write things down as soon as possible after leaving a class or workshop.
Chen Xiaowang says "natural is best." He also believes that until you learn proper structure, you shouldn't try to do tai chi movements in a very low stance. Form and balance are most important. Proper structure is more important than low stances. And it takes us years to get proper structure.
Good kung-fu, he says, is proper structure, not low stances.
There is one principle and three techniques involved in tai chi, according to Chen Xiaowang. He's worded it differently at different times, but the one principle boils down to "when one part moves, all parts move. When dan t'ien moves, the whole body moves."
The three techniques are: dan tien rotates horizontally; dan tien rotates vertically; dan tien rotates in a combination of horizontally and vertically.
There are three languages in tai chi: talking, showing, and hands-on.
Talking can give you some "intellectual" information but it can't give you skill. It can provide some basic understanding, but it can also create a lot of misinterpretations (writing is even worse).
Showing is very important, and can give you even more information and movements to follow and imitate.
Hands-on is where you really develop skill -- the corrections and adjustments to your structure and movement that helps you realize your mistakes and learn to correct yourself.
Many of us want to speed through the process. We see tai chi masters in low stances and we try to imitate, even when we don't have the structure or movement down properly. It sets us back more than it helps (the main benefit is a good leg workout).
Internal arts skill is a marathon, not a sprint. It's good to remind ourselves of this and slow down sometimes, raise our stances higher and work on the fundmentals of structure, the one principle and three techniques, and the body mechanics that will give us skill. Oh, and good corrections are always helpful, too.