Here are some more thoughts:

Consider inflation as a foundation...

People often overlook inflation when requesting a salary increase. The cost of living is almost always rising. If you're going to ask for a raise, make sure you take that into account. (See also: How much is inflation?)

Try to find out how much inflation has been over the time period since your last raise. In order for your purchasing power be restored to what it was originally, you need to win a raise that at least matches inflation. e.g. An offer for a 2% increase shouldn't suffice if inflation was 3.5% over the same period.

...Plus, you're experience has increased. What's the "new you" worth?

Let's say you get a raise matching inflation: You're keeping up, but not actually any better off. How could you have justified more? Consider: your boss now has an employee with more experience, but is paying the same, in inflation-adjusted terms, as before. The new you is a bargain at the old you price!

If you believe increased skill & experience are worth something and are confident you're providing more value for money, don't just aim for a raise matching inflation. Demonstrate how much more productive you are. The list of achievements and salary survey JCarterRN mentions are helpful to make your case.

...Finally, learn how to negotiate.

I really like the book Getting to Yes: Negotiating Agreement Without Giving In, by Roger Fisher & William Ury. There's a good summary of the ideas in the book at Getting to YES – Wikipedia. The book describes principle-based negotiation, objective criteria, and understanding your BATNA, or Best Alternative To a Negotiated Agreement. I find myself re-reading Getting to Yes the night before an important negotiation.

Here are some more thoughts:

Consider inflation as a foundation...

People often overlook inflation when requesting a salary increase. The cost of living is almost always rising. If you're going to ask for a raise, make sure you take that into account. (See also: How much is inflation?)

Try to find out how much inflation has been over the time period since your last raise. In order for your purchasing power be restored to what it was originally, you need to win a raise that at least matches inflation. e.g. An offer for a 2% increase shouldn't suffice if inflation was 3.5% over the same period.

...Plus, you're experience has increased. What's the "new you" worth?

Let's say you get a raise matching inflation: You're keeping up, but not actually any better off. How could you have justified more? Consider: your boss now has an employee with more experience, but is paying the same, in inflation-adjusted terms, as before. The new you is a bargain at the old you price!

If you believe increased skill & experience are worth something and are confident you're providing more value for money, don't just aim for a raise matching inflation. Demonstrate how much more productive you are. The list of achievements and salary survey JCarterRN mentions are helpful to make your case.

...Finally, learn how to negotiate.

I really like the book Getting to Yes: Negotiating Agreement Without Giving In, by Roger Fisher & William Ury. There's a good summary of the ideas in the book at Getting to YES – Wikipedia. The book describes principle-based negotiation, objective criteria, and understanding your BATNA, or Best Alternative To a Negotiated Agreement. I find myself re-reading Getting to Yes the night before an important negotiation.