I have to admit that the only reason I want to go to the MHT is so I can wear a costume at DL. The last time I did was when I was Sally at the Nightmare Party about 3 years ago!
Well unless you agree with the CM who was very unsure if I was wearing a costume of not on Goth Day (I wasn't), it was funny!!!
Super Easy Costume ideas;
Wear your favorite PJ's
Be an old couple in housecoats/robes, guys in shorts, socks and sandals
Wedding Gowns are cheap and easy to find at thrift stores Guys in a bad thrift store Tux.
Dress like you are going to prom with flowers
Dark Suit and be a mortican or Gomez Adams
Black Dress/Robe be a witch or warlock
Cheap Scrubs and you can be a Doctor
I have a bunch more, hehehe! I love costumes and think thrift stores or your own closet are the best places to start. Just use your imagination and you will find something comfy and fun!