This t-shirt refashion was inspired from this tutorial http://elleapparel.blogspot.com/2010/09/socialite-skirt.html
I decided to do a simple pencil or straight skirt using an over-sized men's shirt I found at Wal-Mart for $5.
Step 1: Trace Your Skirt
Take an oversized t-shirt, big enough to fit your waist and hips.
Lay a straight skirt that fits you well on top. Make sure that the bottom of the skirt lines up with the bottom of your t-shirt. This way your skirt bottom will already be hemmed and finished.
Trace leaving a 1/2" seam allowance all the way around.
Step 2: Cut and Sew
Next you will cut out the new skirt following the lines you traced onto the shirt.
Sew up the side seams using 1/2" seam allowance.
Fold over the top of the skirt to the wrong side of skirt a hem of about 1- 1 1/2 ".
Sew this hem all the way around, leaving about 3" open.
Step 3: Insert Elastic
Take your elastic and put around you wherever your new skirt's waist will be on you.
Make sure the elastic is not pulled to tight or too loose. You want it to fit snug enough to not fall off, but not too tight!
Add 1-2" to that measurement.
Insert elastic into casing you just made around the top of your skirt.
Over lap the elastic the 1-2" you added and sew the ends together.
Now close the casing up.