Here are some of the best negotiating tips I've gathered during a decade of writing about money: Be brave. The biggest mistake you can make is to not negotiate at all. Don't make excuses—"The economy is awful", "I'm lucky to have this offer", "I'd rather have a root canal"—and don't fret about being rejected. The courage to negotiate is especially important for women—men are four to eight times more likely to negotiate salary. Most companies are willing to negotiate salary, but most employees never give it a go.
Be prepared.Research a fair salary. Figure out how much you want—but ask for a bit more to leave room for compromise. Practice negotiating your salary. Sit down with someone you trust and role-play the experience. Record yourself so that you can find your flaws. The more you practice, the more you'll feel comfortable during the actual interview.
Be silent.During salary negotiations, it's often best to let the other side do the talking. Using the Chapman Method, when you receive an offer – no matter what it is – follow the offer with "the flinch", a long period of silence. InYou Can Negotiate Anything, Herb Cohen writes," Oddly enough, silence, which is probably easier to carry out, can be just as effective as tears, anger, and aggression." Silence is golden.
Be persistent.In many cases, the employer will reject your first request for a higher offer. Don't let this deter you. Push back gently, justifying your proposed salary. Explain how the company will benefit from the investment.
Be patient.The deeper you get in the process, the more committed the company is to hiring you. Do not mention your current income or your salary expectation—not even on the job application. If you do, you provide an anchor for the negotiation, and that can only hurt you. Wait for the employer to make the first mention of money.
Be flexible.If the company won't budge on salary, negotiate other compensation. Ask for things like an extra week of vacation, a private office, or a flexible schedule. (Maybe you can work four ten-hour days instead of driving to the office five days a week!) Other possible perks include transit passes, educational reimbursement, better health insurance, performance bonuses, or permission to bring your dog to work.
Source : http://lifehacker.com