Here's a trick that saves you money and time: turn a party activity into a loot bag. Since this is a Halloween party, I had the kids decorate Trick-or-Treating bags. I bought orange bags at Michael's ($3 each). I tied a thank-you tag on each (free printables available here!).
I cut jack-o-lantern faces out of felt, and the kids glued on faces, sequins, and small jewels. You can see all the details about these DIY trick-or-treat bags here. The kids all loved this craft.
Next, we played the Donuts-on-a-String game. Oh, look - there are the adorable pom pom spiders I made! This game is insanely easy to set up. The kids LOVED IT. They were practically vibrating with excitement while they waited for me to hang the donuts.
Tip: buy lots of sprinkle ones and lots of chocolate ones. Every other donut was much less desirable.
I also had a bunch of Halloween books out for the kids, which were surprisingly popular! It warmed my librarian heart. I actually got the books at the library, so this part of the party was free.
Next, we played "Pin the Smile on the Jack-o-Lantern." Also crazy-easy to set up - you just need orange and black poster board, and a blindfold.
I got the idea for this giant spider web game from Parents Magazine. All you do is toss some cheesecloth on the ground, then put some big spiders and a 2 x 4 on top. The kids have to walk across the 2 x 4 "bridge" without falling into the spider web!
I'd recommend attaching the cheesecloth to the ground with tent spikes or similar, because it doesn't stick to grass very well.
Next, the kids bobbed for apples. The younger kids splashed and threw apples around, which was also fun.
We also used very cheap toilet paper (4 rolls for $1) to make the kids into mummies, which they got a kick out of. We were going to TP our tree, but my husband nixed it.
For the requisite sugar kick, the kids made candy necklaces. I used embroidery floss, but I suggest something smoother, like gimp (plastic string). Some of the stickier candy caught on the string.
Also, make sure you cut your string long enough so that kids can easily take their necklaces off when they're done.
Some of the kids just ate the candy. That's cool, too - it's Halloween, after all.
At the end of the party, each of the kids got the Trick-or-Treat bag they decorated, their candy necklace, and some glow bracelets to wear while they trick-or-treat.
But the best part was, I was able to throw everything together in just a few days, for a minimal amount of money!