I always have fun at Halloween, because it gives me an excuse to run around in costume.
When I was in elementary school, we had a Halloween Parade every year. Back then, it seemed like for Halloween you had two choices -- either dracula makeup/vampire teeth or you could buy costumes in a box. The costumes in a box were always of a licensed character, and contained a vinyl smock and a thin molded mask which had some elastic to hold it to your face. They don't really make them like that anymore, which is probably a good thing. The masks were quite creepy now that I actually think about it, and they would cut into your face. But those costumes in a box were what seemed like every kid wore for Halloween.
Then somewhere around the 4th grade, when Ninjas and various forms of martial arts became hugely popular, kids started to actually dress up for Halloween. It became apparent that there were other choices that weren't in a box, and the following year, my mother made me a costume of my favorite G.I. Joe character at that time, Airtight. Of course despite carrying around a M-16 and wearing an army helmet everyone thought I was a yellow ninja. A week before Halloween my mother, my sisters and I would pile into the station wagon and head to the mall to the House of Fabric to pick up patterns and materials for our costumes. Any props we needed were picked up at Toys R Us and usually didn't consist of very much. It always seemed quite magical that my mother was so quickly able to transform pieces of cloth and paper into a costume.
A couple of years later, I tried to create a costume of Samus Aran from Metroid out of yellow sweats and some posterboard. It was a pretty lousy costume, and the experience really dissuaded me from costuming for many many years, but it also taught me an important lesson -- you can't throw an elaborate costume together without thinking and planning it out.
Last year, I tried making a costume for an Incredible (from the The Incredibles (given my build I'd have to be Dash), and was pretty happy with how it turned out.
"I see you becoming the greatest of all Jedi" - Senator Palpatine, Attack of the Clones.
This year, I was the Chosen One: Anakin Skywalker. This is the first costume I've made that required me to sew. It's also the most expensive costume I've ever made due to the lightsaber. (Let's be honest though -- I could do with a paper towel tube lightsaber, but it's just not as awesome as a glowing humming lightsaber). This costume (excluding lightsaber) cost about 45 dollars to make, which is 5 dollars more expensive than the Rubie's version of Anakin Skywalker, but mine looks a hell of a lot better, includes a Jedi Robe, and looks a lot more expensive than it actually is.
There's several ways to make a Jedi costume, and the internet is a wonderful resource (given that they have Tutorials on making Stormtrooper Armor, I figured Jedi knight was small potatoes in comparisson). I stumbled upon How to Make a Jedi Robe, took out the sewing machine and got to work. The robe took a couple of hours to sew (I had to learn how to use the sewing machine at the same time) and I picked up the lightsaber at Borders.
I'm really happy with the way the costume turned out (Flickr photoset). I've never liked wearing costumes grounded in reality -- I tend to enjoy the fantastical stuff more. Even if it seems odd walking around, I think it just adds to the fun.