Since I got a sewing machine in 04, I've made a few different costumes. Ironically, I've hardly used it for legitimate projects, such as hemming my favorite pairs of pants or actually mending stuff.
My completed projects include: A set of Gryffindor Quidditch robes and a broomstick for Andi; a set of Ravenclaw Quidditch robes and a broomstick for Sal; a set of My Little Pony pillows for Ginny, Zac, and Cara... for myself, I also made a set of Gryffindor Quidditch robes (and broomstick), a full 'traditional' earth-color Jedi costume (including robes), a Professor Sinistra dress and robes, a military/SF sort of jacket that was symbolic of the X-Men's Phoenix (but in blue and silver), and a less traditional/more original set of Jedi tunics and robes that featured blue instead of the dark browns.
As time passes, I'll be adding photos from these various projects to the gallery with notes on what I did for each one. (The gallery has all kinds of costumes in it, but some stuff from my own costume-making is also there.)