First, start with a drape-front cowl (photo #1) already in your wardrobe, or make one with the many patterns that exist for this style.
As shown In photo #2, turn the garment inside out and flip the facing up to expose the wrong side of front of the top.
Next, pinch some fabric near center front, twist it a bit, and hold the “pinched” fabric with a rubber band, as shown in photo #3. Later, if you want to make this design change permanent, the 'twist' can be stitched. Or just remove the band, and you have your original draped cowl!
Note: A small clear "ponytail" band works well for this!
Now turn down the facing to cover the banded fabric, as shown in photo #4.
As shown in photo #5, when the garment is turned right-side-out, the twisted detail becomes a new interesting design feature of the top!
Where you pinch and band the fabric is totally up to you: higher, lower, to the left or right of center, etc. There are infinite possibilities for design variations like these.... Have fun!