Invitations were Hogwarts acceptance letters, printed in green ink with the party particulars. I made them into parchment by rubbing wet tea bags over them, and sealed the envelopes with red sealing wax. Each invitation was tucked inside of an owl.  The owls were made by cutting and pasting an owl picture from Activity Village.com into a word document.  Each owl was printed with the name of the guest using a Lumos font downloaded from another Harry Potter website. I cut out the owl and glued it to black construction paper making sort of a pocket. For the most part the invitations were passed out at school, otherwise stuffed into a a larger envelope and mailed.  They were a huge hit with other Harry Potter fans.  We began in the living room/dining room area with a sorting ceremony.  I was dressed in a black cape and became Professor McGonagal. The sorting hat was an inexpensive witch hat with facial features cut from craft foam and glazed with glitter.  We used a cell phone tied to a chair hidden under black fabric with my husband in another room announcing one of the four houses as we placed the hat on each girls head. Upon being sorted,each girl was presented with an undecorated wand (hanger cardboard, spray painted dark blue, each party guest's name was written on the wand with a gold paint pen), black robe (men's XL tee shirt cut open with pinking shears) with the house insignia pinned on the upper left side. Insignias (found in wikipedia.com) were printed on my color printer and glued to black card stock, I duct taped a safety pin to the back of each and attached them to the tee shirt prior to the party. Then I stacked them by house to make things run more smoothly.  Many of the girls brought their own witch hats and I had several on hand for anyone who didn't have one.  We had 13 little witches and they looked adorable.  Once sorted, we moved to the basement passing underneath a suspended  purchased Hogwarts banner.  The basement had been transformed into a Hogwarts classroom.   There were four tables covered in black fabric with clear vinyl over each, arranged in a classroom formation. Over each table were house" flags suspended from the ceiling.  The flags were made from black felt and the house insignias (blown up to full letter sized) duct taped to the felt.  Each table had a black and orange spider candle (battery operated).  I had black fabric swags at the basement windows by the end of the party they "grew" a chocolate flower--a tulip shaped chocolate lollypop. Next we began the competiion for the House Cup. We had a chart on the wall with a square for each house.  When someone won a game they were given a "gem" to be placed on the chart next to their respective house crest.   At the end of the party the house with the most gems won the house cup.   The class in charms was "Immobulus charm" was freeze dance: Arithmancy was a word find puzzle from Activity Village Halloween Bingo and guess how many "Bertie Bott's" jelly bean in the jar.  The girls wrote with "quill" pens made from golf pencils attached to craft store quill feathers for the arithmancy classes. The potions class was the baking soda/vinegar experiment.  I found cute little bottles at a craft store with corks for the vinegar.  Each house was provided with one cauldron (deli containers painted black) baking soda (dried unicorn horn) small water bottle with glitter and dish soap (enchanted water from Hogwarts Lake) and vinegar (essence of rainbow--the vinegar was colored with food dye).  The winner of this competion was the house whose "good luck" potion bubbled over the most.  This one I rigged for Griffyndor to win (the birthday girl's house) by diluting the other houses vinegar with water. In one corner we had set up a fortune teller station for "divination" classes.  Two wing chairs faced each other surrounded by more of the draped black fabric and white beads swagged from the ceiling.  For the crystal ball we used a globe shaped light fixture with a very low wattage bulb inside. Our fortune teller Professor Trelawney was an enthusiastic older cousin in a great costume.  We worked in the fortune telling between games so that by the end of the party everyone had their fortune told.We broke at one point for pizza served on black plates with gold stars and drank pink lemonade and apple juice served in black cups. The final game was a pinata with a purchased Golden Snitch hidden inside with the candy. The guest who found the snitch won the gem for their house. The games concluded with the awarding of the house cup to Slitherin. House cups were made from clip art trophies with Hogwarts insignia overlaid ontop. The actual prize was a chocolate frog(purchased online from Vermont Nut Free Chocolates)and packaged to look like the one from the movie for each girl in the winning house.  At this point we had cupcakes and the dirt pudding cups and sang Happy Birthday.  We ended the party with dance music practicing for the Wizards Ball.  Everyone received a Harry Potter Uno Game wrapped in tissue paper in the one of the four house colors.  The key to fitting in all of these activities was being super organized and having all of the games and/or props completely set up. It was alot of work but the girls had a great time and the parents were in awe of the whole thing."