Writing a woman well as a man can be very hard and when it fails it can tell you a lot about that man. The same is BTW true of any minority or subculture that man is not part of.
One good advice: When you start to build a character from a minority or subculture first write the bits that are not (stereo)typical. Just hobbies, likes and dislikes, how they(…) spent their time alone, relationship with parents. That kind of stuff. Only then add the more difficult elements. That way you begin thinking about them as a person first and can avoid the problem of focussing on stereotypes or sexuality too much.
It is not wrong of course to observe and describe other human beings in a sexual way, most of us are sexual beings and often sexually motivated after all but it is wrong if that is the only way you can deal with an entire gender.