A few suggestions- Go directly to the FREE face painting-I remember one in Toon Town, I am sure there were more! My daughter wanted to do this last year and by the time we saw that it was free the line was forever long and the night was half over. She did get a beautiful butterfly the next day at Epcot, but it was NOT free($18)!!
BTW- the strollers, double and single were free last year during the party too, but since the price of strollers almost doubled last week, who knows what this year will bring!
We had a Grand Gathering for my kids 8th and 13th birthdays

and we dressed as follows.... My son(8) was a Power Ranger, daughter(13) was Tinkerbell and my niece(2) was Cinderella. My sister was a black cat, my dad was a grumpy old man(the shirt, hat and cane said it all!)and my mom had a T-Shirt that said "Fairy Grandmother". She was so cute! She had a wand and a Glitter halo. My husband was a doll,

I mean he was....Jack Sparrow

. I needless to say along with my BIL did not dress up.

He is a party pooper and I just plain did not have time to find a costume for myself. BESIDES...it was 90 degrees and everyone that had a costume on had stripped it off by the time of the parade! My son and husband almost had a heat stroke! I was really glad I had on a tee and shorts and not layers of costume!
There are many costume stores online and I also got some stuff from Party City. Dress up and have a great time! Some families we saw dressed together as a theme! There were whole families dressed as 101 Dalmatians and the mom was Cruella! Another family was Snow white and the 7 Dwarfs! The family of Cone Heads were our favorite! People had so much fun with this. It amazed me the lengths some people went to and how simple some ideas and costumes were. The Dalmatians were just white tees and white pants with black dots painted and they made the ears out of ball caps. White face paint and a black eye and nose. Maybe I should have done this one just to black my husbands eye!

You can find great ideas online. Start shopping now and you can find some good deals!
Good luck and have fun!
