So, I had intended to get to this a little closer to Halloween, but I was too busy having fun! I showed you how I made the t-shirt part of H's ducky costume out of a much larger shirt here. Here's how I did the rest!
I used a combination of Alene's OK-to-Wash-It glue and hot glue for putting the feathers on the t-shirt. Both worked fine (since I knew I would be throwing the shirt away, not trying to wash it), and of course, the hot glue dried much more quickly, so I used hot glue for the rest of the project. I stuffed some wax paper inside the shirt before gluing so it wouldn't stick to itself.
I used an adult-sized Hobby Lobby blank tee to make the pants (for cheapness and ease). It was great not to have to hem them because I could use the hem of the shirt! I did make a mistake, though -- I used a leggings pattern instead of a pants pattern. This wasn't a problem, except in the waistband -- because the shirt fabric had way less stretch than the pattern called for. So I ended up with some bunching around the waist. I decided I didn't actually care, though. The pants fit fine, and I don't believe in perfection in Halloween costumes. :-)
For the ducky "tail," I started by basically making a giant scrunchie the size of her waist (out of the scraps from the yellow t-shirt).
Then I cut strips of yellow tulle from a spool, around 22" long, and tied them onto half of the "scrunchie."
I finished by hot-gluing yellow and white feathers to the top of the tail/tutu/whatever you want to call it!
The ducky feet were possibly even easier. I cut four pieces of orange felt into a "duck foot" shape and hot glued around four of the five sides of one, stuck it to another one, then stuffed the opening with polyfill.
Then I took a piece of elastic long enough to go around her ankle, sewed it into the "duck foot" on both sides, and glued the remainder of the hole shut.
For the finishing touches, I used an orange foam visor I got at Jo-Ann's, plus some white and black "foamies" type foam and hot glue, to make a duck bill visor with eyes and girly eyelashes.
And I glued little white and yellow feathers to three small alligator clips to make feather barrettes for her hair.
The costume, front and back:
And in action! The whole costume took maybe an hour and a half to make. H was so proud to be a little ducky. She had the time of her life!