For this project I used:
A women's XL tee, not a fitted tee, it was a roomier cut (depending on the size of your tee and your wear-ee you may need more than one.)
thread to match your fabric
ruffler foot (optional)
Step 1: Preparing Your Tee for Transformation: the Skirt and Waist
Cut 4" from the bottom of each sleeve as pictured as well for the waistband. I know it sounds crazy to use a sleeve for a waist, but keep in mind that this is an XL non-fitted tee and I was making a skirt for a 5 year old. So the sleeve width worked well. In fact, I could have taken it in a couple inches for a better fit. For a yoga wasitband you want it to be a few inches smaller than your waist. If your knit is really, really stretchy you may want to cut it as much as 5", but for a standard tee, 2-3 should work. I know it sounds uncomfortable to make the waistband that much smaller than your waist, but the knit fabric stretches, if there is too much fabric it will be too loose and fall right off! :)
Step 2: Preparing Your Tee for Transformation: the Ruffles
Roll the strips just like you would a long piece of ribbon, lightly stretching the fabric as you go. Now you have the skirt piece (already hemmed with finished side seams, thank you!) The two ends of the sleeves and two rolls of tee-shirt ribbon!
You are ready to sew!
Step 3: Sew Your Waistband!
Note: If you don't have enough fabric or you don't like a waistband you can always do a traditional elastic waist. Just cut your skirt piece 2" longer than your desired length. Fold the cut edge over 1" and sew a channel for the elastic. Insert the elastic and sew shut and you're done. If you choose to do this, skip the next step, attaching the skirt to the waist band and go straight to attaching the ruffles.
Step 4: Attaching the Skirt to the Waistband
Sew the skirt to the band using the elastic thread. If you've never used elastic thread it is easy-peasy. Just hand wind your bobbin with the elastic thread. If you have a top load bobbin, wind it as you normally would a bobbin. :) Then use your regular thread on the needle and the elastic thread in the bobbin and sew using a straight stitch. Now the waist will stretch when it is pulled over hips. :)
Hey, check out your skirt!!! But its kinda plain, don't you think? Let's add some interest!! :)
Then pin the ruffles to the skirt in a spiral to form a big flower. I started off center, just above the middle of the skirt. I chose to take the ruffle all the way around the bottom of the skirt. You can see in the pic that I had a hiccup with my ruffler foot. No worries, just snip off the non-ruffled pieces and overlap where you stop and start. You won't even notice the break in ruffles. :) Then c a r e f u l l y (with normal thread in the bobbin) attach the ruffle to the skirt.
Now you are done!!