From Frank L. Cioffi’s indispensable One Day in the Life of the English Language: A Microcosmic Usage Handbook (2015), comes this sage advice:
The “rules of English” that we were taught, still remember, and even live by provided guidelines for grade-school students, namely, children who were gradually acquiring an understanding of formal English, and who had to be weaned from their childish language. For example, we were taught not to start sentences with conjunctions such as and or so or but. We were taught not to end sentences with prepositions and not to split infinitives. As far more sophisticated users of language, we understand why these rules were created, and though we don’t invariably break them, we also understand that it’s not necessary to blindly or mechanically obey them. In fact, we realize how important it is to routinely question these rules, and to discover their margins and limits.