Putting a comma between a subject and a verb, is not a good idea.

Commas should not be used between one dependent clause, and another.

Many teachers have stated, that a comma should not separate a verb from its direct object.

When listing items in a series, never put a comma, before the first element, after the last element, or anywhere else that would be inappropriate.

A phrase, that functions as a restrictive element, should not be set off with commas.

If your sentence ends with an essential adverb clause, don't put a comma before it, because your meaning will be obscured.

It is better to use no commas at all, than to use one before the word "than."

Although, you might think you need a comma after an introductory "although," this is not the case.

If you are worried about your dark, blue, pen running out of ink, don't put a comma between cumulative adjectives or between an adjective and the noun it modifies.

"Why don't you need a comma after a question mark?," she asked. "For the same reason you don't need one after an exclamation point!," the teacher replied.

If you are tempted to place a comma before a parenthesis, (an urge to which many people succumb), try to hold yourself back.

You might want to put a comma after a coordinating conjunction, but, you only need one before.