Identify alternatives. If more money isn't an option, consider other forms of perks or benefits you might ask for: a spot bonus, a few additional vacation days, tuition reimbursement for some courses you'd like to take, or a better title which may help you as you pursue your next job.
Know your own bottom line. If you're not going to get the raise you believe you deserve – based on your research, your performance, and your conversations with the boss – then it's time to focus on a full-force job search. But don't quit because right now the reality is it's easier to find a job when you have one. Continue to do your job well and simultaneously look for new work.
Finally, if you're out of work now and negotiating for a new job offer, there's natural concern of being low-balled because you've been out of work and you think employers know your options are limited.
But rest assured that the savviest employers won't do this because they know if they severely underpay you, you'll jump as soon as something better comes along. Nobody wants a sullen worker on their hands. And while that may have worked two years ago, it doesn't work now. We're seeing a move away from employers getting rock bottom, cheap labor.
Even if you've been out of work, you should negotiate the offer with confidence, not cockiness. If they've made you an offer, it means they've decided they want you. Thank them for the offer and let them know you're thrilled at the prospect of coming on board, and also ask if there's an opportunity to negotiate. Find out where this salary falls in the range budgeted for this role. Do your research quickly and even if more money isn't an option, perhaps there are other perks and benefits to negotiate.