Today's tip is... You wanna avoid the "All is Lost" trap.
That's when your lead character has no backstory and importance that actually anyone, any character, can step in and replace your lead.
All is Lost can be played by a 20 year-old guy for all we care, or a girl like Jessica Watson, since it has no backstory whatsoever. But noooo... We gotta have this frail old man as the center of this solo-sailing story.
If you choose an unusual character for a lead, there has to be a reason why. And there has to be this development, turn of events, or problems, where it's only possible to happen to your character.
For example, in the TV series Veep, the lead character is a female vice president. One of the conflicts that happened in one of the episodes is that she was groped by the husband of a Finnish politician while she was in his soil. But then, nothing much she could do about it but walked away and later submitted to the situation by saying: "Because this is a man's world that we live in."
This is the kind of problem that only female character feels, which makes your character difficult to replace with another character that is not female. Thus, you don't make a lead character female just for the sake of making them female, but you justify it in your story why you chose to go with this character as your lead.
In short, if you decide that your lead character is not "male, white, and in his prime", in other words, the most common character for a lead, you gotta craft a story where you make your uncommon character irreplaceable.