We all know there aren't enough powerful women leaders in the world, especially the world of business. And we mostly disagree about why that is, with explanations ranging from deeply ingrained gender bias, to the "mommy track" to women's own lack of confidence.

Whatever the explanation, there are things many women do that inadvertently hold us back from the highest achievement, according to Melissa Greenwell, COO of athletic apparel retailer The Finish Line, and author of the new book Money on the Table: How to Increase Profits Through Gender-Balanced Leadership. There are some mistakes women executives make that prevent us from excelling in leadership roles, she says. I've been guilty of every one of these. If you have too, whatever gender you are, you should stop. Today.

1. Not speaking up till you have all your ducks in a row.

Make sure to speak first not last, Greenwell advises. "It doesn't matter if your idea is not fully baked, with all of the possible pitfalls identified," she says. If you wait until everyone else's ideas are heard while you perfect yours, she says, you may talk yourself out of your idea. And even if you don't, you're likely to get left behind when a) the discussion moves on to something else and never returns to your idea; or b) someone else comes up with the same idea and voices it before you do. Either way, you'll wind up kicking yourself.

2. Waiting politely for a break in the discussion.

The point is not to be rude, but to let those you're meeting with know that you have something important to say. If you're having trouble getting people's attention, try using body language, Greenwell says. "Don't slump. Lean forward on the table. Or stand up. Move to the front of the room if necessary. Speak quickly and with energy. Turn up the volume."

3. Relying on electronic communication alone.

Email, text, chat, and phone calls are a godsend for our overloaded schedules. But there's a problem, Greenwell says. "We often miss opportunities to demonstrate our thought leadership and therefore be seen as a leader."

If you're passionate about something, you demonstrate that passion much better by showing up in person, she says. "Anyone can make a point better--more clearly, more passionately, and with all of the supporting evidence--in person. And women need to do this especially because it will increase your odds of being heard, gaining buy-in, and winning your opponent over, particularly if your opponent is a man."

If an idea will benefit from discussion or debate, it's much harder to bat that idea back and forth over email, she notes. Conversely, it's harder for the person you're speaking with to say no to you in person than it is over the phone or (easiest) by email.

Besides, Greenwell points out, "There is absolutely no chance of using body language to your advantage if you can't be seen."

4. Crying.

We throw our whole selves into our work and that means when things go against us we can feel anger, frustration, and sorrow. How we express those feelings matters a lot. "Men raise their voices and swear more commonly when they get angry in the workplace," Greenwell says. "Women often cry when they are angry. You can do that if you want, but you won't be seen as an effective leader. You will be seen as emotional."

Is this fair? Absolutely not. But it is the business world we're stuck with. "There is a double standard when it comes to displaying emotion in the workplace," she says.

5. Playing peacemaker.

"Women have a reflex to smooth a situation over and make a conflict go away," Greenwell says. "It's not your job to make a disagreement disappear."

So what should you do when things get tense? Ask questions, she advises. "Stay engaged, stay focused, and don't become defensive." If the conversation is really going south, then suggest a break and schedule a time to reconvene. Whatever you do, don't avoid the discussion or run away from the confrontation. "Push past that fear," she says.

6. Feeling guilty.

Our always-on, constantly connected world creates boundless demands on our time, Greenwell says. Because we feel guilty about not meeting others' needs, we tend to overcommit ourselves and put our own needs last. "Women who have reached top leadership roles have learned how to push guilt to the side," she says. "That's not to say that these women didn't sometimes feel guilty or perhaps inadequate while trying to balance work and family."

Because we have a hard time saying no to others' requests, we can wind up working against our own interests, she explains. To defend yourself, start by setting priorities for your own time. "Be prepared with a polite 'no': 'I would love to participate but my plate is full right now. I just won't be able to make that commitment.'"

7. Giving up instead of doubling down.

"Don't be afraid to press your point, to press it hard, and to keep pressing," Greenwell says. "You need to get comfortable with the idea of rejection in pursuit of your aim. Women often hate being persistent, because they find this behavior annoying. But men often need to hear an idea more than once to digest it."

Yes, it can be unpleasant--not to mention exhausting--to keep coming back with the same pitch or request or idea over and over again. But, Greenwell says, "You have a choice. Either play to win--or sit on the sidelines and be frustrated."