A couple years ago I made duck costumes for my daughters. They still wear them for dressing up. There are three different costumes and I used (or was inspired by) different tutorials for each. If you have a little one you really can't go wrong with making a duckling costume. This isn't really a duckling costume tutorial but if you know how to sew you can make these.
How to make a duckling costume:
It was so much fun making the duckling costumes. The little one is made from a cotton knit. The top is smocked as well as the very bottom. The ruffled bum used as much fabric as the entire dress. It was worth it. So cute. I simply ruffled a strip of fabric 2" wide and then sewed it on in a circular pattern, sewing along the center where I had ruffled the fabric.
The shoulder straps are shirred as well. All edges have a rolled hem on the serger but you could definitely leave them alone since this is a no fray fabric.
The costume on my oldest is made from a costume fake suede. I used this tutorial for the romper. I added 4 layers of ruffles on the bum. She wore a tutu under the romper to add volume. I really like how it has leg holes. Makes it more of a duckling costume and not a dress.
The costume on my middle daughter is what the girls call the "fancy duckling." The dress fabric is a costume satin. The ruffles are chiffon. The dress is loosely inspired by this tutorial. There are yards and yards of ruffles that circle the dress. The bottom has elastic to give it shape. She is also wearing a tutu under the dress to give it volume.
Now go make yourself a duckling costume!