Think about what is important in your professional and private life, then assess the offer against these metrics.
<ul>
<li>Salary. Even when the money is enough, you need to figure out if it's worthy of your knowledge and skills and in line with the local market.</li>
<li>Job content. Consider whether you will derive job satisfaction from the offer. To answer this question, you need to know the kinds of activities you want to be involved in and the skills you want to use. You will need a deep understanding of what's expected of you to decide whether you do indeed want the job.</li>
<li>Cultural fit. Ask yourself if it is a place where you will be happy, challenged, and where you will thrive. It might make sense to do a trial run to see what your colleagues are like.</li>
<li>Flexibility, vacation, and other perks. Flexible hours and vacation time are an increasingly valuable perk. During the evaluation stage, it's important to find out whether current employees are afforded such benefits.</li>
<li>Other options. Also assess your walk-away alternatives. Think about the offer in terms of the cost and benefit of starting the job search process over again, of staying in your current job, or of first seeing what other offers materialize.</li>
</ul>

Metrics for assessing a job offer

Once you know what elements of the offer you would like to change, you need to decide which parts you are going to press and how you will do it.
If you are dealing with an intermediary, such as an HR administrator or a recruiter, remember not only to make requests but also to ask questions, give information, and share ideas to make the job more palatable.

Negotiating a job offer: Devise your plan

There will be some give and take in negotiations for a new job, but if everything you ask for is a "no," it demonstrates inflexibility on the part of your prospective employer and could be a red flag.
If your internal monitoring system tells you that you should not take the job, listen. However, turn it down politely as they could be potential customers, potential advisors, or even your future employers.

Say no (politely) if the job feels not right

During the stage of the classic negotiation, maximize the cost of the things you are prepared to accept while minimizing the things you're asking for. 
For example, "I'm happy with the role and responsibilities, but I would like to work from home one day per week." Come across as a cheerful but firm negotiator.

Be tough but cheerful during negotiation

The purpose of the interview is to get the offer. The next stage is about considering the offer, then negotiating with your new employer.
Employers need to feel that you are committed. Continue to be enthusiastic in your dealings with your prospective manager so you don't sound uncertain that you want the job.

Commitment and enthusiasm

Think about the offer in terms of your development, quality of life, and the variety of the work you want to do. Think about the trade-offs you are going to make.
When an employer extends a job offer to you, he has psychologically committed to you. You have more leverage to shape your job description and improve your salary and benefits package immediately after you are made an offer than in your first two years of employment.

Commitment and enthusiasm

Similar ideas to Commitment and enthusiasm

Say no (politely) if the job feels not right

Conduct the Perfect Job Interview

Shift your mindset about the job offer