You can be serious about your career without taking yourself too seriously, Rampe notes.

Especially at a firm with no senior women, "you could initiate a discussion group, like a 'Lean in circle,' to help bring diversity issues to the fore," says Rampe.

Impressing a sponsor, so that he or she becomes a fan and "may even be willing to stick his or her neck out for you," Rampe adds, "is often what makes or breaks careers."