What words should not start a sentence?

In the realm of language and writing, there are certain conventions that we often follow to ensure clarity and fluency. One such convention relates to the words that should not initiate a sentence. Now, I must inquire, what specific words do you believe are ill-suited to begin a sentence, and why is it crucial to avoid them? Perhaps it's contractions like "don't" or "isn't," or perhaps it's more about avoiding overly vague or technical terms without proper context. Clarifying these points can significantly enhance the readability and impact of our written communication.