It is true that I have not really mentioned how the issues related to the myths can be resolved. It was done on purpose. When the solution is not there, one tends to think about it. But now that you have brought it up, let us take the myth that says: "The best way to get a raise in salary is to list the reasons why I need more money."
This is not going to help. The reason is that this logic will be applicable to each and every employee of the company. After all, with the increase in the cost of living, everyone's expenses would have gone up. So if the company were to raise your salary because your expenses have gone up, then they'll have to do the same for everyone.
Therefore, the justification for asking for a raise in salary would have to be the other way around - about the company and not about you.
So instead of saying why you need more money, you'll have to show why you deserve more money. The rationale should be employer-centered. Show them the value that you bring to the table. Let your performance speak for you. That will help you get more money.
Of course, after you've given very good professional reasons why you deserve a raise in salary based on your contribution and performance, you could consider using emotional appeals to get what you want!
I would be happy if other readers also came forward and contributed their thoughts on this ticklish issue of asking for a raise in salary after they have joined a company. Under what circumstances is this justified, and how should one go about it?