This top came from a medium standard t shirt. I use to use it for workout so I didn't really want to us it as an everday shirt. Last summer I wanted something to go over my swimsuits while out of the water and decided to grab some scissors and get to work.
-cut from arm pit of sleeve to side of collar and around back under collar on both sides.
-cut from arm pit to arm pit across the back.
-cut back of collar in middle and made two whole about 1/2 inch for both ends.
-used a shoe lace for fastener. [use whatever string/ribbon/lace].
-cut through middle of back. [cut off amount of material not needed to get correct fitting size].
-made holes 2-3 inches apart on both sides from top to bottom.
-strung shoelace corset-style through holes and tied at bottom.
It isn't the best thing you can do with a tee but it's simple for when you need something quick. =)