I have a cream tank top I purchased a while back from Anthropologie and it has a cute ruffle of lace around the bottom. I always thought I could make something similar but maybe with some color, so I gave it a try.
1 yard of material
I started by cutting the material into two 14 inch x 28.5 inch pieces of material. I planned for the skirt to be about 6 inches long, I folded the material in half to make it this way. The reason I cut it 14 inches wide is so I could match up the chevron without any problems on the side seams. I wanted the skirt to be 57 inches around to get a decent ruffle. Since my material wasn't that long, I had to cut two pieces 28.5 inches wide and sew together. When I am making a skirt that will be gathered, I generally go 1.5 times the length around the bottom of the shirt, but if you want it more full, you can go 2 times around.
After I got the material cut, I pinned it up the sides, carefully matching up the chevron.
Then I sewed up both sides and ended up with a loop of material.
Then I folded the material in half and ironed. I wanted the pattern on both sides of the ruffle. I also went ahead and cut it to about 6.5 inches long at this point as well.
I have used this technique many times before...hand-wind a bobbin with elastic thread (trust me it does not take long). Then I sewed the top of the skirt with the elastic thread bobbin in my machine and regular thread on top. This will gather the material for you (you can see this on the back side of my machine in the second picture).
Then I just pinned it onto my t-shirt and sewed it on!
This will look great worn as is or underneath a sweater or sweatshirt with the ruffle part hanging out the bottom.