My cousin and his wife are having a baby boy later this year and are decorating the nursery with a Harry Potter theme. My other cousins and I threw them a baby shower last weekend using the same theme. I dug out some halloween decorations I already had and made a few new things specifically for the theme.
At the front door, I created a brick wall using an XL twin sheet and a large sponge. I hung it from a photo backdrop stand and cut it down the middle so that guests could enter the party through the “wall”. I made the Platform 9 3/4 sign using a chalkboard sign I found in Target’s dollar spot and numbers cut out using my Silhouette machine.
On the breakfast table, I created a Defense against the Dark Arts vignette.
Our version of a Patronus next to the Dark Arts table.
I made a mobile with flying skeleton keys. The keys and mobile came from Amazon and the wings were cut using my Silhouette. 
A welcome banner over the fireplace in Ravenclaw colors.
Potion bottles filled the mantle. I found the labels on Groopdealz and the bottles came from various stores – Target, Hobby Lobby and Goodwill.
The owl lamp and cage were borrowed from the nursery.
A plush owl perched on the mantle.
The food table full of Harry Potter-inspired snacks.
Chocolate Frogs
Our family loves these cream puffs, so I put an edible gold dust on them to turn them into snitches. The wings aren’t pretty, but they are made from melted white chocolate bark.
Bertie Bott’s Every Flavor Beans
The Sorting Hat gift area.
My cousin made the most awesome Hogwarts Express diaper cake with black and red onesies.
The Dementor’s Kiss-away goodie bags next to the front door for guests.
The mom-to-be opening gifts. I put together a baseball themed gift, with a Braves onesie, a crocheted baseball cap, and little navy shoes with baseball patterned toes. I used a baseball easter basket as the gift bag. 
– How can I ever thank you?