You will need:
1) guy shirt, one size bigger then you normally wear (I wear a M, so I picked up a L)
2) a piece of elastic. Wrap a piece around your waist and then subtract about 2 inches from this amount before cutting.
3) a safety pin
4) scissors, Iron (and a seam ripper but this can be optional)
4) a sewing machine or a Lot of Patience
1) Cut your guy shirt in half right under the armpits. Don't be afraid to cut right across a pocket if your shirt has one.
2) Remove those pesky "extra" buttons if you have any with the seam ripper or scissors
3) Decide how you want your skirt to face. Do you want buttons down the front? or none? I've decided to have no buttons on the front, so I've turned my "skirt piece" inside out, with the buttons on the inside. If you want buttons, just do this the other way ^_^
4) Unbutton the skirt piece, then iron.
5) Rebutton. Now we are going to sew the button strip closed! Sew from the top, raw edge of the skirt, but don't sew all the way down. Stop about an inch after the last button. Do this twice, on each side of the buttons.
6) Turn your skirt right sides inside. This means your skirt should be inside out now. Fold down the edges of your skirt. You may have to cut off your topmost button. Use your elastic as a guide when folding, you want the fold to be as large as your elastic, with about 5/8th an inch as a seam allowance. We are making what is called a casting.
Make sure to leave a 2 inch gap in the casting. Don't sew this closed! This will be used to place your elastic in.
You can also use your elastic as a guide when you sew if you are still unsure. Don't sew your elastic to the skirt!
Sew all the way around, minus the 2 inch gap of course!
7) Attach the safety pin to your elastic. Thread this through the casting all the way around.
8) Sew your elastic together.
9) Tuck your elastic completely inside the casting. Sew closed, making sure not to sew on your elastic!
10. Cut raw edges so they are even, and zigzag stitch them so they won't fray.
11) Wheee, warm cotton skirt! =) Wear, or gift to a friend.