Diversity In Writing

An article from Ellen Oh in the recent WriteOnCon set me thinking about how I handle diversity in my writing. 

calabarboy.com

One of my projects is a YA contemporary suspense set in a fictional Southern California high school. This setting practically screamls diversity. Yes, my white main character has a mix of race in his friends and the humorous sidekick is Latin. Though I've included it, have I 'done' diversity right? Have I avoided stereotypes and treated each character with respect? I hope so, but it will be something to check in revisions. One thing I have not done is to reach out to minorities for help in properly reflecting their world. There are probably realistic elements I should add once I become aware of them.

One last thought on this topic concerns writing what you know. Is this why I naturally think of white main characters? We often use the familiar because the whole craft of putting together a story is complicated enough on its own. Or is that a cop out? Maybe it's time to think more outside the box. For me it's a stretch that my MC is male. That takes some 'getting it right' during revisions as well. 

We live in a diverse world. Fantasy worlds should also reflect diversity. How do you use diversity in your writing? Or what have you read that struck you as using diversity well?
Y'all have a great week!