Uhm, it's a tricky one, you could use the following techniques:
- Don't negotiate at the time the initial job offer is made. Thank the employer for the offer and express your strong interest and enthusiasm in the job, but state that you'll need time to evaluate the entire compensation package. Most employers would heappy to give you some time to think about it.
- Do your research. Make sure you have done a thorough job of determining your fair market value for the job you are seeking, the salary range of the job for this specific employer, and company-specific factors that might affect the given salary.
- Always ask for a higher salary (within acceptable limits) than you are willing to accept so that when the employer counters your proposal, the salary should be near your original goal. And when possible, try and show how your actions once you join will recoup the extra amount that you are seeking -- through cost savings or increased sales revenue, productivity, efficiencies.
- Never make demands. Instead, raise questions and make requests during negotiations. Keep the tone conversational, not confrontational.
- Be prepared for any of a number of possible reactions to your counter proposal, from complete acceptance to agreeing to some concessions to refusal to negotiate.