I took this question to the other mods and basically, what it boils down to is this: none of us – male, female, or otherwise – have noticed any real difference between writing male and female characters. The idea that there’s some sort of enforced separation based on binary sex is a little silly, to say the least. Just write your characters as characters!
That’s not to say that gendered socialization won’t play some role in your characters’ lives, of course; they may have different styles of dress, hobbies, interests, etc. because of how they’ve been socialized in their culture. But they’re likely to notice similar things, and the things they might view differently are going to be a matter of experience and education, not gender.
Some of the things we all agreed that we notice upon meeting new people: their voice, their scent, their body language, their attitude. Some people look at eyes first; others look at bodies or the way clothes fit. Everybody’s different in this regard.
Really, truly the best advice I can give you is, forget all the advice you’ve heard about “writing from the perspective of a different gender”. Just write people. Listening to advice like that is a great way to fall into the stereotype trap and lose some of the depth from your characters, so don’t listen to it. Write the best characters you can, and then get feedback from beta readers of all genders and ask them what seemed realistic, what felt jarring, and what you can change to make your portrayals of your characters feel more real. That’s all you really need. Good luck!
-Kyo
Miscellaneous, Secluded Haystack