1. Make it clear what behaviour is acceptable. Value people skills. Promoting purely on technical skills tends to lead to managers with poor managerial skills.
2. Hire and train women. Remember when hiring that women may not have had the same opportunities to learn the latest techniques, which does not mean that they are not capable of doing so.
3. Do your hiring and promotion procedures reward masculine behaviour while punishing women for displaying masculine behaviour.
4. Make sure women have the opportunity to be heard. Specifically, if a woman is interrupted by a male colleague ask to hear the rest of what she had to say.
You may want to pass these tips on to male colleagues.