Whenever I go out to the shops I always look at plain shirts and dresses whenever they're on sale. I got this shirt for $3 from supre. Pretty good :) Here's a tutorial on how to achieve this look.
Lay the shirt flat and mark out the middle of where you are cutting. Then mark out each line, I did mine 2cm apart. Also mark out how far out you will cut to, I did mine in a v-shape.
Cut out the strips, it does not have to be perfect, you won't notice in the end result.
Grab the second strip and place it on top of the first strip.
Pull the second strip under the first strip.
Place the third strip on top of the loop of the second strip, repeat until you reach the end.
When you've reach the end of the strips, take the loop to the inside of the shirt and handstitch it into place.
Now you should be finished :) Here's a photo of me wearing the final product. This technique can be applied to anything, as long as the fabric is knitted and not woven, so it doesn't fray.