This will be a loooooose tutorial on how I made my costume. I decided to just embelish some regular running clothes, instead of running in full costume. There were TONS of people running in full costumes, but I thought this might be more comfortable.
To make the skirt, I folded the material over longways and sewed it together. I wanted double layering on the skirt. (In hindsight, this made the waistband too thick so I probably would go with single layer next time.)
Then I added elastic to the top.
for the pockets, cut 4 half circle shapes out of the white.
Then I safety pinned them to my tank top sleeves on the under side. Pin the straight side to the tank top. My tank top cut way in on the back so I just kind of attached them at the bottom under my arms. I wasn't that worried about how the back looked.
Cinderella nail art :)