My latest Fail (yes, it gets a capital F) was when I tried to create my own version of American Apparel's Le Sac dress. It looked like, well, a sack. (Please excuse the bad hair and lack of makeup - it was early morning but the light was nice). I had all sorts of visions of a stylish dress that could be worn in oh so many different ways - perfect for when I go on backpacking trips for weeks/months at a time. However, reality doesn't always equal your plans... This was the first thing I ever sewed out of jersey fabric, so I didn't realize that I should use a stretch stitch on my machine. Also, the fit was waaaaay too big and super un-flattering. Luckily I was able to salvage the fabric out of it to make a romper (more about that later).
Hopefully you all have more sewing Wins than Fails!