The Mechanics and Rhetoric of Conversation : Page 53

Such subordination is the rhetorical requirement for superior conversation. If you have that, even if you have little else, you will seldom be boring. If you do not avoid at least the most flagrant co-ordination — stringing all ideas together with and and so — you cannot have St. Paul's edge of liveliness, no matter what your knowledge or topic or voice. As the shortest cut to improvement, simply make up your mind not to use and or so noticeably often. Secondly, keep asking yourself which is your most important idea. Then strive to put the lesser ones into phrases and subordinate clauses. It would be highly advantageous if you got yourself a college composition book and reviewed the sections on co-ordination and subordination.1