I started watching anime when The Precious was tiny and would only sleep in my arms. I had to hold her all day long, so that ruled out much movement and led to the need for finding things to watch that had continuing stories. I have found a lot of shows I love, several that drive me crazy, and quite a few that leave me wondering what on earth is in the water in Japan!
Here are some interesting costume ideas from some of the ones I like.
Fullmetal Alchemist Edward Elric Inspired Cosplay Apron Pinafore
Fullmetal Alchemist Blood Seal Pendant
Sadly, I couldn't find any place where you can buy a suit of armour like Al's. I guess that's not surprising though, really. It would be insanely heavy and expensive!
Dressing as Sebastian would be pretty easy--just look for a nice black suit, and don't forget the gloves. You could carry a teapot or flourish a fan of forks and knives.
For Ciel the darndest things come up when you search for costumes! It seems that for some reason, more people want to dress as Ciel wearing his girl disguise than Ciel in his normal Victorian boy's clothing. Who knows. This seller seems to have done a great job in making one of the dresses though.
Handmade Ciel Dance Dress
If you'd like to be Ciel in his regular clothing though, there are several options. This is probably my favourite but if you are looking for the others, they are on the same site.
CIel Phantomhive Black Suit Cosplay Costume
Oddly enough, I found an Undertaker costume on Etsy. I'm not sure how you'd manage to sharpen your teeth appropriately though.
Undertaker Cosplay Black Butler
If you wanted to dress as your favorite over-the-top, completely mad, man-chasing redheaded undertaker, yep, there's a costume for that too. It is in men's sizes but I'm thinking it will look more appropriate for the character if a female wears it. Will you choose a chainsaw or dual-wield scissors?
Gureru Sutcliffe Cosplay Costume
If you are a woman who wants to dress as a female there's always the screechy, clumsy maid, Meirin, who has a secret talent. Make sure that your glasses are easier to see through than hers are though, or you really will have a scary Halloween!
Meirin Cosplay Wig
Maylene Cosplay Costume
Spice and Wolf
I think if I ever go to a convention and am not dressed as something from Tolkien or the Whoniverse, I will probably be dressed as Horo/Holo. It really wouldn't be that hard!
Brown Long Fur Leather Wolf Dog Ears
Green Cloak Cape
Peeking from the bottom of the cloak, you'd need this.
Custom Furry Tail
Wear a little pouch containing wheat around your neck and carry an apple!
Really, I think only guys will be able to pull off the Ginko look. The clothes would be very easy--he usually wears a white long-sleeved button down and khakis. Wear a backpack and white wig. Ginko is usually smoking, so you could carry a hand-rolled cigar or cigarette (not sure which it is), but I think it's best not to encourage smoking. That one is your call.
I have a horrible feeling that I'm leaving out some great costumes, but I'm going to have to stop there. I realize that anime costumes are usually reserved for conventions,but why not wear them for Halloween?