The best practice is inspired by theory.

The designer of a new kind of system must participate fully in the implementation.

The sun comes up just about as often as it goes down, in the long run, but this doesn't make its motion random.

My general working style is to write everything first with pencil and paper, sitting beside a big wastebasket. Then I use Emacs to enter the text into my machine.

Premature optimization is the root of all evil.

When certain concepts of TeX are introduced informally, general rules will be stated; afterwards you will find that the rules aren't strictly true. In general, the later chapters contain more reliable information than the earlier ones do. The author feels that this technique of deliberate lying will actually make it easier for you to learn the ideas. Once you understand a simple but false rule, it will not be hard to supplement that rule with its exceptions.

It is much more rewarding to do more with less.