I really wanted to make a fantastic costume for UshiCon 2005, so I went with Etna because she's such a great character. I think the hardest parts of this costume were the boots, wig, and top.
The boots were originally black leather spray-painted grey...but it took only a few hours of walking around to make all the paint flake off, so I bought some Ugg-type boots and souped them up in one night. The wig is actually 2 wigs: separate pig-tails super-glued and sewed into the wig base. And "got2b glued" is the best product out there for this type of hair! The top I bought from a biker leather store and then I just tailored it.
I tell you what, for my first cosplay costume ever, I think I did pretty well. Everyone at UshiCon really loved it and I had a lot of fun getting glomped and photographed.
Honorable Mention Novice at Katsucon13