From what I've seen, it doesn't work like that. Sure, there are stores and areas that are better than others, but a large part of it is random chance. I was finding very little at on of my local stores, but I kept it in my rotation. Then one day, *Wham!* — new 1982 Grenson balmorals for $20 that fit me perfectly. I found three pairs of shoes for myself that weekend. The odds just fall in weird patterns like that.
Some stores get donations from the immediate area, others from a central distribution, and others a combination of the two. If you are really interested in doing this, visit them ALL for yourself. Do the work, and it is work. It may be fun work for some of us, but when you see a post from Andro, Brian, or any of the other guys showcasing a week's worth of treasures, you don't see all the times that they may have walked out of a store with nothing in hand. Some guys will also do a mix of thrift, estate sales, garage sales, live/online auctions, discounters, and so on. They generally don't walk out of just a store or two with armfuls of Italian suits.
Give it a while before you make a judgement as to the quality of drops, especially if you are coming up on a seasonal change. A lot of store are rotating in fall items right now that they've been holding on to in the back. Talk to the people working in the store to see what kind of intake they have (local, central) and if they have any kind of schedule or just put out pieces as they get them. A lot of stores have a rotating color sale. Keep track of the color of the week so you know what's coming up for the next week. If you find a suit with a $20 blue tag that you are on the fence about, and blue will be on sale the next day, it might be worth waiting if you can get to the store early the next morning.
Above all, it takes patience and perseverance. It's not a get-rich quick plan, despite the great finds you may see here. It's not even a get-clothed-quick plan, unless you are willing to wear just anything. You can just stop in a store when the mood hits and see what they have, and that's a fun way to do it, but that's not what these guys are doing. They are making the consistent great finds because they are maximizing their odds of finding great stuff, and it's more than just what store to shop at.
As barrelntrigger says, have fun with it. Keeping expectations low goes a long way with that.