Start with 2 tank tops (or even 2 shirts if you want) that are made of a no fray jersey or knit material ( so that you wont have to hem anything). I am using these two old A shirts that my husband doesn't wear anymore.
And that's it! Walk out the door and move on! You have a new shirt! Put on the shirt with the holes and then put the cumberbun part over those holes! You get extra bonus points if you have a belly band from your pregnancy and don't have to cut up a second shirt! How cool is that! You can also use the same cumberbum you just cut out on other shirts!