Most Latin abbreviations in English have faded out of newspaper copy. A few remain. Simon's rule was that a journalist who uses a Latin abbreviation should know exactly what it means and should use it only when the English version would be clumsier.
e.g. vs i.e.
e.g. is short for exempli gratia, "for example." Use it when you are introducing one or more examples from a larger set. "Tropical fruits, e.g. mango and papaya."
i.e. is short for id est, "that is." Use it when you are clarifying or restating something more precisely. "The senior editor, i.e. the deputy editor in Keith's absence."
They are not interchangeable. Mixing them up is one of the faster ways to mark yourself as someone who does not read carefully. Plain English versions ("for example" and "that is") are almost always better in news copy. Save the abbreviations for parenthetical asides, lists, and reference material.
In Australian style, write them with full stops: e.g. not eg, i.e. not ie. A comma often follows when they introduce a phrase, but house styles vary. Check your style guide.
sic
Sic is Latin for "thus" or "so." It is used in square brackets inside a direct quote to signal that an error in the original is preserved deliberately. "She wrote: 'I was dissappointed [sic] with the response.'"
Use sic sparingly. A piece full of [sic] notices looks smug. If the error is minor and does not affect meaning, silently correct it or quote around it. If the error is important, use sic or quote around it and gloss the error in your own words.
Do not use sic to mock. A journalist who quotes a speaker and marks the speaker's regional dialect with [sic] is being a snob. Reserve it for cases where accuracy demands it.
etc. and etcetera
Et cetera is Latin for "and the rest" or "and other things." The abbreviation is etc. with a full stop. Never "ect." Never "etc" without the stop in Australian formal style.
Use etcetera only when the reader can easily fill in what the rest of the list would be. "Fruits like apples, oranges, etc." works. "Government departments like Treasury, Home Affairs, etc." does not, because the reader cannot tell whether you mean other central departments, portfolio departments, or something else.
In news copy, "and so on" is often clearer than "etc." Editors who came up through the press gallery will tell you that an etc. in a news piece is a sign of lazy reporting: you ran out of examples and did not want to admit it.
Other abbreviations you will see
cf. ("compare"), academic. Rarely used in news copy. Use "compare" or "see also."
ibid. ("in the same place"), for citations only. Not used in news copy, which does not use footnotes.
op. cit. ("the work cited"), academic. Not in news copy.
viz. ("namely"), very formal, old-fashioned. Use "namely" instead.
N.B. ("note well"), use "note that" or start a new sentence.
AD and BC (or CE and BCE in some house styles), these are fine, still widely used. Check your style guide.
A general rule
If you would be embarrassed to write out the Latin longhand, do not use the abbreviation. If the English version is clearer, use the English. Latin in news copy should be a sparse garnish, not a diet.
Simon's version, from an old memo he passed around the features desk: "If the reader has to pause to translate, the writer has failed."