(CBS) — If you want a bigger paycheck, just ask for a raise, right?

But a lot of women don’t.

That may help explain why even though they make up more than half of the workforce their average weekly earnings are $300 less than men in the same jobs.

CBS 2’s Dorothy Tucker has some advice for women who are looking to get paid more.

Tracie Willis thinks she deserves a raise, but she has yet to ask for it.

“It’s something that right now would scare me a little bit,” admits Nicole Bazinsky.

She, too, is still waiting.

Their reluctance is not surprising to life coach Lisa Kaplin.

“They don’t want to be difficult or demanding,” she says.

Don’t think your boss will offer you a raise just because you deserve it. You have to ask.

“The mistake a lot of women make is they add some fluff. … They say ‘I’m sorry to bother you, but I want to ask for a raise.’ It really diminishes the request. Say your line with assertiveness and authority,” Kaplin advises.

Most importantly, do your homework. Know your market value. Know how much of a raise you want. And be prepared to prove your worth.

Kaplin urged women to make a list of accomplishments for their employer.

“We think it’s bragging, but it’s not bragging,” she says.

It worked for Alyssa Graver. She recently got a raise and a promotion to managing director at a financial consulting firm.

“We went through it and ultimately they said, ‘You presented your case in a very professional way,’ and they made it happen,” she says.

A couple more tips: Don’t compare your accomplishments to your colleagues, which could come across as childish. And, don’t just barge into your boss’s office. Instead, make an appointment to discuss your request.