You don't have to be confrontational about it, if you do you are doing it wrong.Thinking about asking for a pay rise. Don't know how! Haha hate confrontation.
Initiate it in a professional manner, outline your reasons for wanting it, not just "because I want more money" back it up.. are people elsewhere being paid more? could you easily leave and get more money somewhere else?
Would it be hard for your boss to find someone to replace you, much training time involved to get them upto speed? basically if there is a 3-6 months involved in getting someone trained up for the job to be able to work independently than your boss would need to take into account that he is not just losing you if you were to leave, but he is impending on the ability of another staff member who will need to take time off what they are doing to check the work done by the new person/train them. This is a pessimistic approach and should probably not be the first method you use, maybe start with accomplishments on your behalf that you believe are reasons you should be considered............ Every work place will be different.