1.) Choose a Theme
Suggest that everyone come dressed as their favorite Disney villain, their favorite insect, or their favorite fall food (think apples, squash, pie, hot cocoa, etc.), or if the guests are a little older, suggest that everyone come dressed representing various decades. This will make for some great photos, as everyone's costumes will go together.
A great set of decorations will take your party to the next level, but you don't have to spend a ton of money on decorations. Get your kids involved. Hang streamers in purple, black, and orange, or make paper link chains to hang from ceilings to walls throughout the party area. Purchase some spider webs from the dollar store and hang them in your corners. Wrap some empty toilet paper rolls in medical gauze and glue on googly eyes for easy mummies. Leave your leaves on the front steps and set out some pumpkins in various colors. Cut out some bat-shapes out of black paper and tape them on the walls. If you want to stick with fall-decor, set some candy corn in glass vases, tiny pumpkins and pinecones in lanterns, scarecrows (make one out of old clothes and newspapers), and make banners from twine and orange/brown/white fabric scraps.
3.) Make-Your-Own Pizza Bar
Make several pan-sized pizza crusts (or purchase store bought dough, or even English muffins if you want an already-made crust). Print out some ideas for Halloween-style decorations and set out the appropriate toppings. Search Pinterest for various ideas to make pizza spiders, pizza jack-o-lanterns, to cut out ghost-shaped mozzarella. Bonus: make-your-own-pizzas doubles as a fun party activity.
4.) Rent Silly Halloween Movies
Think Hotel Transylvania, It's the Great Pumpkin Charlie Brown, The Corpse Bride, Hocus Pocus, or Double Double Toil and Trouble. Play them all through the party as people mingle. An alternative would be to play the movie later in the evening and have everyone snuggle together to watch.
5.) Plan Some Activities
Give some classic party games a Halloween spin for a surprising and entertaining night. Paint orange cones to look like candy corns and set up a ring toss (consider dimming the lights or playing outside after dark and using glow stick rings). Draw eyes and a mouth on clear plastic cups and set them in a pyramid for a Halloween-style game of milk bottle toss. Have a worm-pie eating contest (gummy worms and green whipped cream! No hands!)
Planning a Halloween party doesn't have to be complicated. What are you waiting for? Start sending out those invitations!