Sell Accomplishments
Approach the boss to sell your accomplishments. Reiterate your experience that adds value to the organization and let boss know how you helped cut costs and increased productivity. A written record of your accomplishments from your own personnel files helps to document your achievements and can make it easier for your boss to get approval for a raise.
One way to impress your boss, for instance, is giving an option that would sound attractive to him like you taking extra responsibility for an additional amount per hour. Providing options kindles interest and shows you are not merely talking about your paycheck but concerned about the organization too. This proactive approach indicates you are worth the raise.
However avoid two things: Don't ingratiate or adopt an attitude that without a raise injustice is being done to you. Also implying that being there for a long time entitles you to a raise in fact could mean that all you did was marking your time to get the raise.
Know Your Worth
Never fail in doing your homework. If those working with you are earning more than you in similar roles chuckling at your salary offer that means you should be asking for more. Check out salaries at recruitment firms, in job ads and on salary surveys online and find out if people with your skills are dime-a-dozen or if employers would fight among themselves to have you.
Time it Right
Never disturb you boss when he is busy. Time it right when your employer is not busy servicing customers. Let some time interval pass before you ask for a raise. Or else the boss could rebuke you saying a raise was given just a month or two ago and it could mean prospects for a raise in future receding.
Learn from your mistakes
Failing to convince your boss does not mean you cannot try again. Be cordial and let him see your positive attitude and there is chance that at the next renegotiation you could be a winner.Be brave. And never get taken by false or underpaying job title like 'Vice-President, Global Sales', or that offers promotion opportunities. Get paid what you're worth. Your chances of success are when you time your renegotiation right.