Step1
Set the perfect tone for the party immediately with the right invitation. Write it as a request to attend Hogwarts School of Witchcraft and Wizardry. Write or print it on parchment paper so you can roll it up as a scroll and even seal it with a blob of wax.
Step2
Ask the guests to come dressed as a character from the books. Adults keeping the kids happy can dress as the main professors from Hogwarts --Dumbledore, McGonagall, Snape and Hagrid.
Step3
Decorate the world. This is pretty easy since you can pull out and use all your old Halloween decorations again. Just make sure to have candles, broomsticks, snakes, owls and bats. For a special Harry Potter touch, paint ping-pong balls gold to represent the main Quidditch ball, the Golden Snitch, and hang them around the hours with clear thread or fishing line.
Step4
Make sure the student houses that make up the Hogwarts School are given a prominent position in your decorating efforts. If you and your kids have time and the craft expertise, make banners with the house colors--Hufflepuff: yellow and black; Ravenclaw: blue and bronze; Slytherin: green and silver; Gryffindor: scarlet and gold–and write the names of the houses on them in Gothic-style lettering.
Step5
If you're allowing the party to wander through your house, you can represent the geography of the books with signs in different rooms. The kitchen is obviously the “The Leaky Cauldron,” the living room “Diagon Alley,” and the bedrooms can be “The Forbidden Forest.”
Step6
Where will the Sorting Hat send you?
When your child’s guests arrive, sort them into Hogwarts Houses using the Sorting Hat. Either put the kids’ names in the hat and assign them to a house when their names are pulled from the hat, or write the names of the houses on folded pieces of paper and have the kids pull them from the hat to see which house they belong to.
Step7
Make magical foods like the ones you can buy in the Leaky Cauldron or in Hogsmeade. Label food with magical names–"cauldron cakes," “magic wand pretzels," “spider spawn,” “rat tails,” “bloodworms” and so on.
Step8
No Harry Potter party will be complete without Butterbeer. Make it the way you would root beer and ginger ale floats, pouring the soda over a scoop of ice cream. Other magical drinks can include “Polyjuice Potion”–and since “poly” means more than one, that about covers any mix you can think of–“Dragon’s Breath Punch” and “Sleeping Potion” (made with Kool-Aid, of course).
Step9
Have magical things to do. Set up a table as Ollivanders Wand Shop and allow the kids to make their own wands. Give them straws, chopsticks and long twigs for the wand itself, and provide them with yarn, feathers, sequins and glue for them to add "Unicorn Hair," "Phoenix Feathers" and "Dragon Scales" to their creations.
Step10
Organize a magical treasure hunt. Before the young wizards and witches arrive, hide magical items–chocolate frogs, dragon eggs, love potions and at least one Sorcerer’s Stone–around the house. Make the treasure hunt more challenging by making up riddles to give clues to where the various items are hidden.
Step11
Prepare a quiz based on the Harry Potter books and divide the kids into teams for a Tri-Wizard Trivia Tournament.
Step12
Play Charades based on the Harry Potter books, movies and characters.
Step13
Many ordinary muggle games can be turned magical with a little bit of imagination. Relay races can be organized with wands instead of batons, capture the flag can become catch the snitch, and so on.
Step14
If money is not a problem hire a professional magician–a wizard–to entertain. Tell the magician the party will have a Harry Potter theme, so the magic tricks can be performed in the context of the wizarding world.
Step15
Organize a major project as a finale for the party. For instance, you could get all the kids to participate in making a dragon (Norwegian Ridgeback, Hungarian Horntail or the Swedish Short-Snout, your choice!) Have lots of cloth and pains handy to make the skin and conga line the dragon through the house when it’s finished.