I'm sorry your skirt didn't work out! Ship it back to me (unwashed and unworn, please!) at 1446 N Estrada, Mesa, AZ 85207 within 21 days.
You can ship through USPS just fine but I've discovered it's significantly cheaper to go through PayPal. I've added instructions below because it's not super intuitive (my sister had to walk me through it. Twice).
Log into your PayPal account
From your account home page click the link on the lower left that says "MultiOrder shipping".
Deal with the angry pop-up gods
You'll probably have to turn off your pop-up blocker and tell it that the browser you're using is acceptable. This thing is rife with pop-ups and it doesn't want to work properly if your blocker is on.
Create a new order
Click that little button right there.
Fill out your order details
In the Order Details section: Include your order number (should be in your original confirmation and shipping emails)
In Shipping Details: In the Service Type/Package drop down menu select Package/Thick Envelope under the heading "First-Class Mail Parcel Service." Unless you've packaged your skirt totally differently, the weight should be under 7oz.
Add shipping info
Add my name and shipping address in there then add your info in the "Ship From Address" tab.
Then click "Save and Close".
Select your order
Click that square on the left.
Pay and Print
Follow the instructions to print your label. Tape it to your package then drop it in the nearest mailbox!
I'll look it over as soon as it arrives and issue a refund asap.