…After I realized that a self-insert was not working for me and that I could no longer keep up the pretense. xD My first character was unintentionally intertwined with myself as is often the case for new roleplayers. It just took time for me to grow personally and mature as a writer. As I did, I became more brave to branch out and try writing new character concepts and personalities. I also realized that how I was portraying my first character was simply cringeworthy and embarrassing. It was garnering negative attention as people did not take my character or me as a person seriously.
I love thinking about concepts in WoW that you could not possibly do in real life which therefore gives you a bit of separation. The Warcraft setting offers such a great parameter to shape your characters and make them a part of the world. I also take inspiration from history, books, movies, operas, and even lore characters to incorporate some details into my characters.
I am also of the belief that it is okay to add elements of yourself (and arguably impossible to completely separate yourself from your character). As long as it is not overwhelmingly your own traits, it is fine. I do not think people should force their characters to be drastically different. It is natural to draw from what we know. We should challenge ourselves, but do what feels comfortable and natural—otherwise it will stop being fun and start feeling like a chore.
What a thought-provoking question with some already great tips mentioned in this thread such as reading and research. 