From a young age I've learned to write both genders. I liked to write stories when I was a child, and well, it feels weird to write a story where everyone is male. Perhaps as a child, 80% of my characters were male and 20% were female, but as a grew up and began to take storywriting more seriously, my characters started to trend towards a 50-50 distribution between both genders, specially during my teenage years where I started incorporating romance elements into some of my stories.
I've never had too much of a problem playing either gender, and while during roleplaying I do tend to prefer males as main characters, though I will still play female leads when required. When doubling, tripling or more though, I have no problem having a few females as part of my main cast. As side characters I play both genders equally. I think it mostly boils down to the fact that I prefer playing a male if I only have one character to play as, but I feel free to play both genders if I have multiple characters I can use.