I re-did another shirt and this time I took pictures along the WHOLE process so that it wouldn't be confusing. If you didn't understand the last instructions, it should be clear this time. I am going to do this quick.
I re-did a maternity shirt that I didn't want to get rid of and wanted to have it be a little more flattering. First I measured where the center of the shirt was and put a pin in it ( also, I am doing this with it wrong side out )
Then I took a piece of elastic and sewed it down on one side.
Looking at the picture you can see that I leave the pin in the shirt so you can see where the center of the shirt is. I use a zig zag stitch to get it sewn down on the side
Next, you want to take the elastic from the end that isn't sewn down and stretch it down to where you want it to be.
Notice how it is ONLY sewn on the sides and not down the center
Now you want to sew the center down. Put it under your sewing machine and then pull the elastic tight.
Sew down the center and you are done! It should only take ten or fifteen minutes. It looks SO much better and you can't tell it is a maternity shirt any more. What an easy fix.