Getting a job offer can be a joyous experience. However, there are times when you get an offer, but it's not what you really want. Perhaps the pay is too low, or the work isn't exciting enough. Whatever your reason, if you decide to not accept a position, then you should learn how to politely decline.
Please don't use the "it's not you, it's me" bit.
You might find yourself wanting to make vague excuses in an attempt to let the employer down easy. But, similar to dating, if you've ever been told, "it's not you, it's ME," then you know that's the cowardly way out. You're saying "no" to this job offer for a particular reason, and the employer will want to know what it is. That said, it's how you explain what's holding you back that will impact whether they'd ever consider you for a job in the future. Don't assume you will never want to work there. The job market is a lot smaller than you think. Times change, and so do your needs. Thus, how you handle this rejection will determine whether they'd ever consider you again.
Stick to the facts and be sincere.
When we decide to not take an offer, it's important to explain objectively why it isn't a good fit for our career goals. As I always tell clients, think of yourself as a business-of-one who needs to make smart decisions so you can stay in business. Turning down a job opportunity means you feel it won't help your career stay healthy and on track. For example, let's say the pay they offered you is too low. What you don't want to say is:
"This offer is too low. I'm worth more and feel you don't value my worth."
The response above sounds emotional and negative. Instead, you'd say:
"Thank you for this offer. I'm so pleased you feel I'm the right fit for the role. That's why it's difficult to tell you this, but I must turn it down. Unfortunately, I have a certain income level I need to earn to cover my financial obligations. I couldn't take this role without feeling concerned about my commitments. Again, I appreciate the offer and hope that you might consider me for future positions that might be a better fit. I really respect and admire the company and would love to work here someday."
By explaining truthfully the reason for your rejection, and sandwiching it in between gratitude and appreciation, you can make the rejection easier for the employer to accept. Better still, by telling them truthfully what's holding you back, you might just find them willing to make some concessions on your behalf. Keep in mind, they just chose you for the job. The idea of going back to the drawing board to find another you isn't all that exciting. At this point, they might decide meeting your criteria would be the faster, better solution.
P.S. - No hiding behind email or text!
One last piece of advice - never try to do this via email or text. Nothing screams, "I'm a coward," more than not picking up the phone and telling the employer directly you can't accept their job. It's important they hear the sincerity in your voice. In fact, it could be this type of accountability and professionalism that gets them to want to make concessions you need to say "yes." So, suck it up and call them - it's the right thing to do!