We had a Harry Potter party for my son's 4th birthday this year. I printed the invitations on scroll paper that I purchased from Staples. It said, "We are pleased to inform you that you have been accepted at Hogwarts School of Witchcraft and Wizardry for one day of magic to celebrate Anthony's 4th birthday.  Your day of magic will be on mm/dd at time. Then it listed the party address.  You must enter between platforms 9 and 10.  We await your owl no later than mm/dd.  Signed, my name and number, Headmistress for a day." Page 2 of the invitation said, "Hogwarts has chosen Anthony's birthday to host a legendary event, The Triwizard Tournament!  The tournament will consist of 3 challenging tasks.  The adventure begins at the Sorting Ceremony to determine which school you will represent at the Triwizard Tournament. Be prepared for a full day of magical events!  Eternal Glory awaits the team that wins the Triwizard Tournament." I bought a white table cloth and used red paint and a sponge to make a brick wall (platform 9 3/4), which we hung in the doorway. Once all the kids arrived, we had a Sorting Ceremony(I purchased a sorting hat on ebay).  I wrote out on cards which teams the kids would be on, Hogwarts, Beauxbatons or Durmstrang. The kids had to find their name. I placed the sorting hat on their heads and they read out loud what team they were on. Next, I had classes set up for the kids to attend. Each school was in a different class.  After they were done, they'd move onto the next class. The classes were:  Potions, Herbology, Divination and OWL (wizarding test). For potions, I had the kids mix their choice of polyjuice potion (a root bear float), pumpkin juice (orange koolaid) or dragon snot (green sherbet and sprite).  For herbology I bought each kid a small flower pot.  I wrote on each pot, Mandrake.  The kids had to repot Mandrakes (plant flowers). For divination I used a garden gazing ball as a crystal ball and I got a full size cardboard cutout of Harry, Ron and Hermione.  I made each kid put on a Harry Potter costume(purchased at my local party store), stand in front of the cutout and next the crystal ball to take a picture. The OWL(ordianry wizarding level) was a test that I made all about the Goblet of Fire.  The team with the most correct answers won a prize.  I set up Olivander's Wand shop for each kid to choose a wand. I made the wands (chocolate covered pretzel rods with the tips dipped in white sprinkels). I set up Honeydukes Candy Shop where I had different Harry Potter candies (purchased on ebay) and chocolate lolipops that I made using Harry Potter molds. I had a jar filled with jelly beans set up for the kids to guess how many.  The winner won a prize. I also had set up Flourish and Blotts. I printed off the internet coloring pages and puzzles and made them into a book.  I attached a crayon to each book. The kids got to get their book to sit and color while I set up the Triwizard Tournament. I started the tournamet by hiding a dragon for the kids to find. (I bought 3 small dragons from toys r us)  Each team had to find their dragon(each dragon was a different color) attached to the dragon was a note that said, The objective was to get their dragons egg. The teams secrect keeper was holding the egg (I had 3 adults be the secret keeper for each team) They got 2 clues to help them guess who the keeper was. To get the 3rd clue, they had to place their dragon in its nest (everything was color coded) in the nest was the 3rd clue, which led them to the keeper.  (Clues were: I drive a white car. My birthday is in January, etc.) First team to find the dragon, figure out who the secret keeper is, and get their egg, won the 1st task. The second task was the spoon race.  Each team used their dragon egg to play.  They put the egg on a spoon and each kid raced across the yard and back to their team.  The first team to finish won the 2nd task.  For the third task, I placed notes inside balloons.  The kids had to run across the yard, pop the balloon and get the note.  When all the notes were found they had to arrange them correctly to read the riddle, "Harry's lost his glasses, now he can't see, maybe they're hidden. Where can they be?" Then the kids had to find Harry's glasses. I had someone in the room wearing them.  The 1st team to find the glasses won the 3rd task.  I bought little trophies for each of the kids and wrote on them Triwizard Champion.  I purchased, on ebay, boxes that were personalized with Harry's picture and said Anthony's 4th Birthday,for the kids party favors. They were allowed to go to Honeydukes and pick some candy. The kids loved this party.  Even the adults had a blast.