Simple posters, in blue colour way, with a rhyme describing magic 'e' and, the alternative term used in some schools, bossy 'e'. Clearly laid out with examples for each vowel. Available in a choice of fonts.
Middle school bulletin board idea: "Believe in your #selfie" Have each student take a selfie and put it up with a #adjective that describes them. "Do something today for which your future self will thank you." The kids love seeing their faces in the hallway and it builds a grade-level community too.