A lot of students worry about whether their accent will affect their score in the Speaking section of the TOEFL. Well, it’s like this. Everyone who speaks English has an accent. So, having an accent is not a problem.
What matters more than accent is clarity. Now clarity itself is composed of two elements.
The first element is that you must overcome any obvious mispronunciation. This means learning to say “yellow” and not “jello” if you’re a Spanish speaker. Or learning to say “rice” and not “lice” if you’re Japanese, for example. These are examples where the mistake actually produces a different word, and can cause confusion.
An example where a mistake due to accent does not produce another word is when Eastern Europeans say “Vas iz thiz?” instead of “What is this?” The meaning is still understandable, though there are errors due to the accent. This is less of a problem.
The second point is that you must speak as clearly and confidently as possible. Sometimes when students are nervous or forget the word they want to say, they try to mumble their way through. This is not a good idea, and doing so repeatedly could cause you to lose points because you are not communicating effectively. Better to find another word or explain what you mean as clearly as you can, in whatever accent you do have.