Readers appreciate lists because they present information in an easy-to-digest manner. Given the increasing speed of communication – and the growing impatience of readers – lists are more commonplace today, even in essays. Remember that two fundamental English principles lead the way: Choose the simplest, most direct form of communication for the reader's sake and be consistent with your choices.
Decide whether your list should be integrated in a paragraph or set off with a colon, with each successive sentence or clause on a separate line. Short lists can often be contained within a paragraph. Here's an example: “She came to class without any of the tools the teacher required: acrylic paint, brushes, poster board and paper towels.”
Create a list with multiple lines when you have lengthier information to convey, either in sentence or clause form. Set off this information with a colon, capitalize the first letter of each item and single-space the list.
Use lists with multiple lines only when you have three or more lines of information. The conventions of English dictate that two points – no matter what the content – aren't significant enough to merit the kind of attention that lists generate among readers in the first place.
Create a parallel structure for your list, ensuring that the first word on each line is a noun, verb, adverb, gerund or infinitive phrase. Mixing structures will cause the reader to pause and stumble, defeating the purpose of creating a list.
Use bullet points to preface each item in your list. Bullet points have largely replaced numbers, but there is an exception here, too: Use a numbered list only if you plan to refer to certain information in the list later in the essay. In this case, a numbered list is a courtesy to your reader since referring to “point No. 6 on page 4” makes it easier for a reader to jump back than making him count the bullet points himself.
Keep end punctuation to a minimum with your list. In this way, too, lists have evolved over the years. Each line should be self-contained and not require a semi-colon or period at the end. The exception: long-winded sentences and those in which the list, read as a paragraph, make punctuation a necessity for clarity's sake. In this case, end most lines in the list with a semi-colon; end the second-to-last line with a semicolon followed by the word “and” and place a period at the end of the last line of the list.