Your Accent
Nobody can actually help you with this. As amusing as other people’s attempts to “do an American accent” are—America is a vast country with a variety of accents—the tone of your voice is still a dead giveaway. And whatever you do, don’t try to pass it off as a “local” accent. Unless you’re a linguistic genius, it’ll sound terrible.
Trying Someone Else’s Accent
Of course, when you’re attempting not to sound American, you sound the most American. We’re renowned for believing that we can sound exactly like the people around us. And it’s at this point that we use an Australian accent in London or a Northern accent in Wales. If you try this in the United Kingdom, you should realize that being likened to Dick van Dyke is not a compliment.