I'm a non-native English speaker and I somewhat deliberately mix different parts of American and British English. For example, I usually use American spelling,

I'm a non-native English speaker and I somewhat deliberately mix different parts of American and British English. For example, I usually use American spelling, but for some things (like "toward" vs. "towards") the British way (or rather the way which is more common in Britain compared to America) sounds "more right" to me. I also put commas/periods outside quotes because I could never understand why they should be inside.