I did manage to make a dump truck costume for my first born. Three boxes, some crazy glue, a quart of semi-gloss, and a sharpie. He was definitely impressed for about five seconds.
This was the first Halloween I bothered dressing anybody up. Joseph was a baby for his first and second Halloween; last year I had three day old twins so we pretty much took a pass.
Violet's costume was an elf hat (pattern from Bend the Rules Sewing) and a play silk from Joseph's school. I'm not totally clear what she was supposed to be (some sort of pixie or fairy, I suppose) but it was cute.
Poor Harry didn't even get a makeshift costume; he just got another elf hat and some grainy photographs.
The babies cooperated and kept their hats on for hours. Halloween magic, I tell you.