IBM has a program to teach women how to network and showcase their capabilities, because the company's research showed that women are less active than men in doing that internally and building their influence. Success is "both about our work output, and how you're seen as collaborating and leading," van Kralingen said.

Hammonds warned women against keeping their heads down while doing a job and then not telling the story of what they and their teams achieved.

Push for the flexibility you need. Flexible work environments are a hot discussion topic, fueled by Yahoo CEO Marissa Mayer's decision to no longer let employees work at home.

Hammonds said about half of Boeing's IT workforce works virtually in some way and noted that employees' needs change over time. "Men and women are going to go through life phases -- sicknesses, elderly parents, children -- so allowing that flexibility is very important," she said. "And they'll be better performers if you stick by them in that time of need."

Flexibility goes beyond work-at-home options, Terrell said. If members of a small project team want to schedule their own time for how they need to work, employers need to figure out how to let them. "It behooves us all to look at flexibility because it draws talent, and it enhances innovation," she said.

Lack of flexibility might keep women from doing that self-advocating noted earlier. "People might hold themselves back because they don't want to work the way they see us working," Jordan said. If a company can show that there are flexible alternatives, more women may push to advance.

Make mentoring a two-way street. Wal-Mart has created "mentoring circles," as opposed to one-on-one mentor-mentee relationships. Those groups of 15 to 20 women, including at least one senior leader, get together monthly to discuss what it's like to be a woman in technology. Wal-Mart created the circles because so many employees wanted access to effective mentors that it became impractical to do that one-on-one. Plus, it then becomes more about creating a group of people leaning on each other. "It's probably the most meaningful element of retention that I can see between those we lose and those we keep," Terrell said.

But don't make the mentoring a one-way street, van Kralingen advised. If you're the junior person, work on providing feedback that's valuable to the business leader.