The common uses of the subjunctive mood are for "
Contrary to
Fact"
statements. The "If there were..." statements mentioned in other writeups are
Present Contrary to Fact. They represent a conditional statement which is not true. Another good example of this is, "If I were you..."
Future Contrary to Fact also uses the subjunctive. These imply something that is not going to happen in the future. e.g. "If I were going to go, I would..."
Past Contrary to Fact does not use the subjunctive. Rather, it is expressed using the
Past Perfect Indicative. e.g. "If I had gone..."
Optative statements, those of
wishing, do in fact use the subjunctive, though many people do not use it correctly. They are an
extention of CtF. As in: "I wish I were
rich. I could buy my way to
Pedant level." The (false) condition is implied through the wish.