Brian Kernighan's Programming Style Tips

• Say what you mean, simply and directly.
• Use the ``telephone test'' for readability.
• Write clearly - don't be too clever.
• Don't use conditional expressions as a substitute for a logical expression.
• Parenthesize to avoid ambiguity.
• Each time you make a test, do something.
• Follow each decision as closely as possible with its associated action.
• Use the good features of a language; avoid the bad ones.
• Capture regularity in control flow, irregularity in data.
• Each module should do one thing well.
• Make sure comments and code agree.
• Don't just echo the code with comments - make every comment count.
• Don't comment bad code - rewrite it.
• Use symbolic constants for magic numbers.
• Watch out for side effects and order of evaluation.
• Macros are not functions.
• Watch out for off-by-one errors.
• Test programs at their boundaries.
• Program defensively.
• Make sure input cannot violate the limits of the program.
• Make it right before you make it faster.
• Keep it right when you make it faster.
• Don't sacrifice clarity for small gains in ``efficiency.''
• Don't stop with your first draft.

[From The Elements of Programming Style, Kernighan & Plauger, McGraw-Hill, 1978]
Note: this book is still well worth reading- even though most of the examples are in languages that you probably haven't heard of, the principles are universal. -DJE