This shirt/tank style is everywhere (Obesity and Speed/Wang)--shit. I love how tore-up and gauzy the t-shirt knit becomes after tugging and tearing away at it. This is Zana from Garbage Dress who is AMAZING and love her stee-low.
Here's a really basic how-to. Easy-peasey nice and breezy. *think* ripping/running a pair of nylons and there you have it.
1. Find a cheap white t-shirt. Preferably cotton/poly blend. 60/40 or 50/50.
2. Use a seam ripper to take out a tiny thread and pull it, creating a slice 1/4in-3inches long. Then begin to pull, rip and run the material like nylons or pantyhose all the way down.
3. This is the end result. Not that hype on white (too pure)...think I'll dye it black/grey maybe uneven tie-dye (without ties).