Sometimes it can be hard to diversify characters. If they show up in your mind as straight, and cis, and white, sometimes there's nothing you can do about that. That's who they are. And that's okay, because there are people who are straight and cis and white!

However, sometimes it's good to try new things even if it feels a little forced. A beginning writer will always make their characters a lot like them. I'm sure all of my characters were white girls (and/or reindeer, as I recall) when I was younger. But I gradually came to realize that I wasn't being diverse at all - so the first thing I did was experiment with the characters I already had. What if this character was black or Asian instead of white? I ended up really liking that character coming from an Asian background. And as I continued, it gradually got easier and easier for me to just create characters that were diverse. They'd just show up in my mind as such. So, even if it feels awkward at first, checking off boxes is a great way to start!

As for your first problem - Google is your friend. If your character is going to be very culturally diverse, just search up customs! Read blog posts and family recipes. Learn as best you can! And remember - even if your character is different from you in race, sexuality, or gender, that doesn't mean their life is insanely different from yours. I'm sure you've written white characters who didn't grow up with parents who were like yours. Plenty of diverse households are just . . . households. The only differences you'll find are in things you probably have experience writing anyway.

I hope this helped! And it's great that you're thinking about this, GW! <3

Top!

I’m not going to reiterate everything St. Owl said, but I agree. 

One thing I find helpful is watching a show/movie or reading a book with good diverse characters. Try to notice what makes them different. Make sure to not have your character’s whole being centered on their diversity. 

Sorry I don’t have a lot of advice to give, but I have noticed myself getting better with writing different characters.  

Have a great day/night!

-Night 

St. Owl and Nighthawk already gave some great advice, so I just wanna add one thing (that you've probably already thought). When writing someone different from you, someone of a different ethnicity, race, sexuality, gender, religion, or anything else, remember that that shouldn't be the only thing about them. Everyone is more than their surface. Sure, being Black/gay/Wiccan might be a big part of someone, but they've still gotta be their own character. You don't want to slack off in their depth just because it seems like they've already got a thing. 

This is probably one of the most messy and incomprehensible things I've ever written. I hope I've effectively communicated my thought... 

kwoi 

This is all really good advice! As someone who struggles with wanting to make diversity realistic, I sympathize. Here's something that's helped me-- reach out. I know that you said that you don't have very diverse friends irl, but what about online? There are plenty of people of all nationalities, colours, sexualities, and gender identies, here and on NaNo. Why don't you try them? If you don't know who to reach out to, come find me on YWP NaNo (do you have an account there? Are you on the CB classroom?) and I can point you towards some people who have helped me before. If you don't have an account, well, we can work around that.

Best of luck!

~Starseeker 

Not all non-white characters will have a culture is super different from yours. I don't know where you live, but for an example, I could write an asian character whose entire family has lived in America for many generations, so her culture is just the culture of whatever part of America she lives in. If she lived in DC, which is close to where I live, it wouldn't be hard to write the culture correctly. 

G.W, this happened to me once. I had a similar moment (only with straight caucasian females as opposed to males), and began to, well, freak out.

You don't have to.

I'm involved in a novelist/writing website where people post their stories and quizzes. A lot of people seem to like diverse stories and more diverse characters--but you don't have to add them in your current writing.

Adding diverse characters to a pre-planned (or being currently written) story might just mess it up. It's just adding filler characters. If you're writing a story, you're writing to tell a story. You likely already know how a lot of that story will go, and will probably want to tell that story. Adding a diverse character, as opposed to changing a current character/etc, might throw that story off-track. It might change your vision for that story.

So if you want to add diverse characters, make sure it's in future writing, and not in something already written. That way the story goes smoothly.

...Yeah this probably sounded weird. I'm not great at talking about this. 

This is something I work on a lot; well, my characters don't tend to be straight, but they do usually end up white even though I'm mixed race. Here's my tip: Write it. With your straight, cis, whatever. Then, very simply, pick a character and change their appearance to be non-white. Then go in and edit descriptions of their appearance to fit their new race. Maybe put in two or three thoughts about it in the book, and change names of family members to the translations. (Ex. Grandma= Nana, Buba, Nani) Unless it's an immigrant family, you probably won't need to change that much (ex. if a family has been in America for more than 100 years, they're going to be American).  

I did this with my character named Avi- I wrote the first. written draft with her white, then in the graphic novel I simply made her a black girl. She's an orphan, so that was pretty easy as I didn't have to do much culture. At some point I mention someone being slightly racist towards her and her reaction, in another part a little bit about her hair, and that was that. Diverse, and non-forced/stereotypical because I'd written her as white. (She's also lesbian, but that was easy. It would've been harder to make her straight.)

I haven't written much for real, but it seems like most of my character concepts tend to be either female or genderqueer, and they're even more often not straight. *shrugs*

If it helps, here are some tidpits of advice that I learned from my mom, who's a media justice lawyer.

A lot of the time, people will describe an African American character as black in the initial character description, for example "she grabbed the cup with one coffee-colored hand, and tucked her long black hair behind her ear with the other. Or, "he was tall, with cardboard colored skin and dreadlocks. He wore a read shirt and jeans." And then just not describe the skin tone of white characters, and let the reader assume their race. You know, because white is the norm. "She had pretty blue eyes, and short brown hair. She wore a necklace with a bead shaped like a heart on the end of it and a dark grey sweatshirt," etc. If you look around, you'll see this actually happens a lot. Unless it's a plot point, it's kind of rude for the author to shove: "Hey! This charcter is black!" type of deal in your face like that.

Also it's apparentley a stereotype to have an Asian sidekick.... 

Sorry of that was kind of confusing.