Construction on this & my friend's Espeon dress are the same! I modified a butterick bridal pattern (don't have the number on me, all of my patterns live at my parents' house when I'm not using them, sorry!) for the bodice. For Vaporeon, we followed the same concept and just scalloped the skirt instead of leaving it plain, and our Leafeon actually recycled an old dress she had on hand - all I made were the light green & brown bits, the trim, and the ears!
The skirts for Sylveon and Espeon are just full circle skirts which we trimmed with lace. I hand patterned our ears, as well as my bows, and feelers, and a full writeup on these can be found here: http://fancyduckie.tumblr.com/post/127399757907/sylveontutorial Everything is made out of casa satin with the exception of my blue inserts for my ears and the bias tape/blanket binding on my feelers.
I ordered the gloves off of amazon because my mom took me to get a manicure for my birthday and halfway through getting my nails painted purple (my actual favorite color), I was like "well shoot these don't match my cosplay for this weekend" lol. I also ordered pink shoes with bows & new lenses but they didn't come in on time for the concert. ; A ; But I did have them for AB and I'm so happy because they're super cute AND comfy!
Overall, really easy, really comfy, and only took about 12 hours a piece to make over three days!