Recently I have found an interesting video on one YouTube channel dedicated to this topic. In fact, it was related to men. But I have an peculiar love to male items of cloth and accessories. Recently I've met a boy who has 3 of the same pairs of shoes as me and he asked me if it is him to be too feminine. Today these borders are absolutely blurred. A lot of fashion houses does not divide their runway shows exclusively on "men" and "women", a lot of women dress like men and the world include them into lists of "it-girls". I believe that it is becoming more and more popular today because: a) it gives more diversity to your style and b) it is very intellectual and smart component of personal style to build your look so that you will look feminine in men's clothing.
During several years of this passion I came up with some most important rules (in fact, I can talk about it for hour!). It should include a lot of details like neat (optionally, messy) hair, accurate hands (especially hands with nice but not glaring manicure), feminine perfume, may be some lipstick or eyeliner (choose only one). The rest depends only on your tastes.
Also the most important advice is: even though, you wear masculine cloth, you should act 100 times more feminine comparing to those times, when you wear a dress with heels and a lipstick.