Invitations:
Black top hat with removable bunny popping up out of it.
Write information on the bunny, or try using white crayon
or wax paper writing and have them color it
with crayon to reveal the magic message.!
In invitation, You can include a magic trick for each to be rehearsed and performed during the party

Cake and Foods
Decorate with a top hat and a magic wand or a bunny. Serve chips or other snacks in plastic top hats

Decorations:
Black and white balloons, streamers and tableware.

Goodie Bags
Add simple magic tricks, cards, small book on magic tricks. If you can find them, use plastic top hats to put the goodies in.

Games And Activities:

Craft
Make ahead black capes with the kid's names in glitter and a few glitter scrolls (ahead of time so they are dry). Let the kids glue on precut stars, swirls, sew on buttons, jewels, even iron on jewel designs are available.

Magician
Hire a magician or let the kids perform small tricks. Dress up a 'stage' area for effect.

Disappearing Kids
Race using teams. Give each a roll of toilet paper and have them completely cover one team member. First team done wins.

Balloon Animals
Have a balloon pump and lots of balloons for the kids to try their hand at making animals or have someone make them for the kids.