If you look at the personalities around you, the ones owned by your friends and family, you will see this played out. Almost all (actual-people) personalities are a combination of masculine and feminine traits. Some of them may repress those traits to a greater or lesser extent (more on that later), but by and large they are combinations. The reality of the situation is that much of gender is culturally based; what counts as "masculine" or "feminine" depends on whom you ask, and where you ask them, and when (more on that later, too). When you get down to it, people are people; write your character as a person first, a gender second, and you're good to go.
