When my husband threw several shrunken black t-shirts in the GRO (Get Rid Of) pile and took the boys off for the morning, I jumped on the rags with glee and started hacking away. T-shirt reconstruction is so liberating that way. One shirt (the rattiest) became a base skirt that the ruffles were then sewn on to.
To make a simple base skirt, look for a tutorial somewhere (Any suggestions?) or do as I do. Cut the top off a t-shirt that you will be able to fit around your hips right under the arms. I like to cut one side about 1" higher at the top than the other to accommodate my rear. Make sure you can fit the tube over your hips! Now find some thick elastic and hold it comfortably around your waist. (You can always use to top of your husband/boyfriend/brother's boxer shorts!) Add 1" and cut. Join ends overlapping 1/2" and sew securely. Fold in half and half again and put a pin at each fold so that the loop is marked in four even lengths. Do this for the skirt top too. Now turn the skirt inside out, slip the elastic inside the skirt and line up the pins from the elastic to those of the skirt and pin together. Sew the elastic to the skirt with a zig-zag while stretching the elastic to be even with the fabric. Now turn the skirt right side out, flip the elastic to the inside and sew again so the elastic is encased.
Now the fun part! Two more T's are cut freehand using a rotary cutter (or scissors) into flounces shaped like a thirds of a donut, like this:
I connected these into large loops made from three or four lengths and trimmed the edges to be even and then pinned them on the skirt starting at the bottom.
As you sew, stretch the skirt fabric so it is even with the flounce and sew with a zig-zag stitch. After sewing each flounce, pin the next higher row. You can adjust the lengths of the flounce layers by cutting off excess fabric or adding in length.
Try it on, and adjust the length (with the scissors--no hemming).
When my darling came home and saw the shredded remains of his shirts on the floor surrounding a randomly-ruffled skirt he said, " I didn't EVER think my old shirts could look like that." (I'm not sure if it was said with awe or shock.)
I used one stained, faded shirt for the base and two that had just shrunk into short boxy shapes for the ruffles. This is the prototype, and it has some wonky bits. I made the back of this skirt a little bigger than the front to accommodate my rear, then accidentally modeled it backwards, so the front is a bit saggy in the photo.(I guess there is a valid reason to put tags in clothes.) Overall I think I could put this on frontwards and wear it out of the house--at least at night, to a dark place, perhaps by scooter?