One thing I know I wouldn't do differently is attend this party! This party was the best of the three I've attended at Walt Disney World: Mickey's Not So Scary Halloween Party, Mickey's Very Merry Christmas Party and Mickey's Pirate and Princess Party (in that order!). This party was full of so much fun- from the treats, the parade, the fireworks and the costumes.
Another thing I wouldn't change is dressing up! Our group decided to go as Carl, Russell and Dug from up. My son decided at the last minute not to wear his costume. He said Dug was scary! Luckily, I planned for this and had a tshirt made with Dug's picture on it that said, "Hi, I'm Dug... But I won't wear my costume!" If you go to this party, I would HIGHLY encourage you to dress up. We saw everything on all ages, sizes and shapes. Many groups were dressed as Disney characters, but others weren't. We saw groups dressed as board games, cowboys and Indians, Super Heros, sports figures, food items and animals. There were lots of Pirates of the Caribbean characters, Princesses, Fairies, and Haunted Mansion Ghosts!
The first thing I would do differently at MNSSHP is not ride the rides. While we didn't spend much time at all on attractions, it did take up time and I should have used that time to do things that guests can't do on a normal operating day. The only exception to this "rule" is the Haunted Mansion! We did not ride it this time because Cman was too young, but if your kids can handle the Haunted Mansion, I think it's a must for this night!
I would suggest getting a seat for The Boo To You Parade early. If your party isn't too large, you could have a member in your party save your spots on the parade route while the rest of the group grabs a snack or hits the Trick or Treat Stations. I would also suggest viewing the first parade. Then if you missed the pictures you wanted or if your kids want to see it again, you can catch the later parade later. This parade route gets full quickly. Do plan to stay through the end of the parade as cast members pass out candy to the kids who are on the front few rows of the route.
As for the Trick or Treat Stations, we spent a lot of time early in the night getting candy. Cman loved trick or treating, but it took a good bit of time out of the night. I know we can't do this on normal operating hours, but we can buy candy any time we'd like. One thing I did notice was later in the night the cast members were wanting to get rid of candy, so they were handing out bigger handfuls. My suggestion is to save the Trick or Treating for the last hour of the night. The lines will be shorter and handfuls are bigger!
Along with the Boo To You Parade, I would encourage you to see the Hallowishes Fireworks show! This show had a Halloween twist to the normal Wishes show. You can view this show anywhere on Main Street in front of the Castle.
One thing we missed that I regret is the Villain's Dance Mix and Mingle in front of the castle. This is a Halloween show featuring the Villains. Following the show, the Villains come meet and greet guests. We were able to catch the last 5 minutes of the meeting time when we saw Gaston.
If you have younger children who like to dance, I would suggest visiting the Character Dance Parties! We had a lot of fun here and Cman had a chance to dance to the entire song, "Who Let the Dogs Out" with Stitch! While I would participate in these, choose your dance party wisely. Look at the party guide and decide which characters your child would enjoy more. We spent time at the Tomorrowland Dance Party and if I had known it would be such a hit, I would have rather danced with Woody and Jessie in Frontierland.
When I do this party again this is my plan:
1) Arrive early so you're ready to go as soon as the party starts. Be in costume and decide which of the character meet and greets is most important to you and get in line. Hint: choose a character who will only make an appearance at the party and not daily in the parks. I wish I had met Flynn and Rapunzel. This could take up to an hour.
2) As soon as you have met this character, visit one of the Dance Parties and dance for a while.
3) Eat dinner if you haven't or grab a snack. Depending on the time, you may want to start marking your spot for the early parade at 8:15.
4) Following the parade, hit a few trick or treat stations or visit some characters who have shorter lines. Be on Main Street for the Hallowishes show early enough to get a good viewing spot.
5) Hallowishes is at 9:30. After the fireworks, stick around Main Street for the Villain's Dance Mix and Mingle at 10:05 or hit the trick or treat stations in Fantasyland and Tomorrowland, but be back in time for the show!
6) Following the Villain's, you can stay on Main Street if you want to view all or part of the Boo to You parade at 10:30.
7) Trick or Treat, Dance Party or Characters. You choose which is more important to you at this point! Villains will be back out in front of the castle at 11:15.
8) ENJOY your night!