You have heard the advice: be yourself! I am not going to bore you by saying something as trite an cliche as that. But, I do want you to look at it from a slightly different perspective.
So many people come to me thinking they have deficiencies in their speaking, especially due to their accent. People will ask me how they can cut down on their Southern or Bronx accent and sound more professional. I have two things to tell you: one, that is very hard and two, I have no evidence that it really matters.
Well, I am thinking about a woman who is 5″1′ tall, in her 70s, has a strong regional accent, and maybe 20-30 years ago, would not have been deemed suited for TV appearance. Who am I talking about? Judge Judy. She earns millions of dollars by doing part time work as the most successful TV talk show host in the country or even the world.
So do not tell me that your accent has to sound like a MidWestern broadcaster in 1985 who grew up in South Dakota. It does not matter what your accent sounds like, as long as people can understand you and believe in your message as you convey it in a compelling way, you can succeed.