There are a number of things one should do before negotiating a salary raise.   Assess one’s place in the company and in the industry.  Think of how valuable you are to the company.  Once those things have been settled, then its time to work on your salary raise.

The first thing to do is to talk to the person in your department, be it a supervisor, departmental head, or whatever, who has the authority to give a raise.  See where the talks go.  Is your boss immediately open to negotiating raises?  If not, ask if there are things that can be done to earn more money while working at your employer.  A number of things may come up, such as applying for a job within the company that pays better, increasing your job skills (such as certifications, degrees, etc).  A number of large companies have benefits such as tuition reimbursement that help develop their employees.

Another thing that will help is always keep your professional networks open.  If you’re offered another job, and your work is valuable enough to your employer, they will give you a counter offer to retain your services.  If the counter offer is sufficient, you’ve successfully negotiated a new raise.   If not, congrats, you still have a new job.