Commas are not to be sprinkled about in a composition as though, like salt, to add flavor. The tendency of modern writers is to use commas sparingly. You should be able to show either that the commas you use help the reader to read what you have written or that they are required by custom—as in a date or address, for example. Using commas just for the fun of it is as bad as not using them when they are necessary. Your teacher will surely question your competence if you use them in places where they cannot be justified.
Chapter 34 Punctuation, Endmarks and Commas, Unnecessary Commas, Evidence in Warriner's English Grammar and Composition Revised Edition, Complete Course, John E. Warriner and Francis Griffith, 1965