I'm currently working on my Masters in Business Administration, and I came across a passage from my organization textbook that I feel could be useful for a lot of people here. It's called "How to Project Confidence With Your Words". As we all know, confidence is both a major attraction factor for women and equally important in our work life as well.

Rule Explanation
Always know exactly what you want. The more committed you are to achieving a certain end, the more clearly and powerfully you will be able to sell your idea.
Use the pronoun I unless you are part of a team. This allows you to take individual credit for your ideas.
Downplay uncertainty. If you are unsure of your opinion, make a broad but positive statement, such as "I am sure this new accounting procedure will make things more efficient".
Ask very few questions. You make come across as being weak or unknowledgeable if you have to ask what something means or what's going on.
Don't display disappointment when your ideas are challenged. It is better to act as though opposition is expected and to explain your viewpoint.
Make bold statements. Be bold about ideas, but avoid attacking anyone personally.

These rules are good for projecting a basic air of confidence in your interactions. While the examples given apply more to work than to personal interaction, the same rules can be used effectively in personal situations. Use these basic rules in your interactions to project confidence with your verbal communications. Remember, however, that this only covers a small portion of what you're communicating. A large part of your communication is nonverbal! There are other good sources of information on nonverbal communication.

TL;DR Come on, I even made a chart. There's no excuse for not reading this post!