From the very beginning incorprates the uses of alliteration, she names the founders of hogwarts "Helga Hufflepuff, Rowena Ravenclaw, Godric Gryffindor, and Salazar Slytherin." Rowling tends to use alliterations when it comes to names of either people or places. The school founders aren't the only characters with alliterated names others include Minerva McGonagall, Cho Chang, and Filius Flitwick. She does this so that names would be easier to remember since so many characters exist in her world. In Rowling's book Quidditch through the ages she introduces the different kinds of Quidditch teams found around the world and each of them have an alliterated name, sme examples are the "Vratsa Vultures," "Woollongong Warriors," and the "Gimbi Giant-Slayers." Alliterations are found greatly throuhout her work but she usually limits them to names.
Something found profusely throughout Rowling's work would have to be her use of symbolism. One major symbol would have to be Harry's lightning shaped scar on his forehead. This scar represents Harrys connection to his past and with his enemy, Lord Voldemort. His scar is what also makes him unique and also connects him to the love of his deceased parents. Other important symbols would have to be Rowlings use of the colors red and green. Throughout her series she always references these two colors, green is seen as bad and red as good. The colors of Gryffindor House sre red and gold (Good) and the colors of Slytherin are green and silver (Bad). There is always a conflict between the two colors, in Harry Potter and the Goblet of Fire Rowling write, "A jet of green light issued from Voldemort's wand just as a jet of red light blasted from Harry's..."
Rowling uses allusion in abundance in her series. She mostly alludes to works of mythology, legend, folklore, and history. For example in her novels we find creatures such as mermaids, centaurs, and sphinxs, all of these dealing with various myths. One important allusion would have to be that of the three-headed dog, Fluffy. This dog is very similar to the one found in Greek mythology by the name of Cerberus, who guards the underworld. Another allusion could be made about the name Hermione in the series. Rowling has said she found the name from Shakespeare's A Winter's Tale, similarities could be made from both characters. Both Shakespeare's and Rowling's Hermione were turned into stone.
One very important device used by Rowling would have to be foreshadowing. In Harry Potter and the Half-Blood Prince Rowling first introduces Dumbledore having a blachened hand. This is clear foreshadowing of Dumbledore's future death in the novel. Another example of foreshadowing would have to be Ron's "fake" predictions. Throughout the novel whenever Harry Potter's friend makes a humorous prediction it in some way becomes true. For example he made a "fake" prediction of him drowning but then he finds himself a pawn in the Triwizard Competition resulting in him almost drowning.