Yes. There is. I think building a character that is great is part of a beautiful craft that needs to be mastered.
I never make a character with the intention of having him/her be gay. I start with the basics, like if they're human, are they from Earth, did they have parents, were they born in America...just basically create a rough sketch of an idea for them to help know what type of story I'll do and how the character reflects that.
Then, I'll decide more about their specifics. Are they male or female? Do they grow up rich, poor, or somewhere in the middle? And, most importantly, what does he/she want?
So, with that basic guide, let's try it out as if we've been asked to do a comedy/action. Alright, well where's the protagonist from? Let's say Germany. Germany is a nice place with a history's worth of regret. Perhaps that can reflect something the character did. So yeah, Germany. Usually you should pick a specific part of you location that helps get an idea of your character's upbringing, but for brevity's sake, let's say Heilbron. Our character probably lived in a small village near it.
So we have a character's background and where they are from. This is where I depend more upon what "feels" right to me, and my mind for whatever reason is saying that this character is a girl, probably twenty-seven. Her parents were probably raised by people who experienced WWII first-handedly, so her parents in turn might be stricter than what we're used to. She lived in a village near Heilbront, her parents maybe like to farm? That would give her a reason to want to dissociate from them--she wants to visit the world, not farm. Instead, she's still there, twenty-seven, and farming.
Now of course, we know her. She wants out of her traditionally family life-style so she's a bit rebellious, she's young and wishes to see the world, and is sick of her normal life.
Now tell me, does she sound more likely to be straight or gay...or will she turn gay?