One of the biggest mistakes ...

One of the biggest mistakes women make in business is that they aren't friendly enough.
 Charlotte Beers

Quotes from the same author

The most common mistake you'll make is forgetting to keep your own scorecard. Very little at work reinforces your ability to do this, so you will have to be vigilant. When evaluators give you an assessment, they are just guessing at who you are; they certainly are not the ones who know your potential. They can rate you and influence you, but they don't get to define you. That's your most honorable assignment: to define, every day through the way you deliver your work, the scope and nature of your inherent abilities.
 Charlotte Beers
Being in charge of your work life doesn't mean you always move with assurance and sublime self-confidence; it means you keep moving, continuing on your own path, even when you feel shaky and uncertain.
 Charlotte Beers