Think about more than Salary
If you feel confident that you are worth more to the organisation you work for than your current pay packet, there is nothing to stop you asking for a raise in the right way.
However, don't always think about the bottom line of take home pay - there may be other ways in which you can get more value from the company with regard to other benefits that might be more palatable to them whilst just as valuable to you, if not more so.
Things to consider include bonuses, commissions, share options and so forth. For instance, if your bonus level is usually capped at a certain rate then rather than get more salary, suggest that if you do exceed your targets that you are get another couple of percent bonus. This way you are showing that you are prepared to put in the work if you get the reward accordingly as a result.
There are also other benefits to consider such as holiday - so if you want another of couple days holiday a share then consider asking for this rather than simply more pay per se. Still other options may be working hours - ask for more flexibility with your working hours; many would value this more than just a little more in their pay packet; if it's important to you then by all means ask for it.
In other words, broaden your horizons and don't just think about everything in terms of your overall pay packet, and you should do just fine.