People who can go to the sup stores take pictures through the windows to id whats releasing, or people just look at the uk store in the morning.
You keep hitting refresh until they update the online store with new stuff around 11:00 EST
Click what you want, add to cart, and checkout as fast as you can. programs exist to put in your address and card info so you can save time.
This is only for hyped stuff, so some products sit in the store for weeks.
Items also randomly restock so you can sometimes get them if you were too slow the first time.
Essentially if you want something with hype behind it have the right things installed and know what you're buying before the store gets updated