To put it simply; Ideal curbside scrapping would be zero competition! Seriously, one would find literally tons of scrap / other great items if it weren't for the 50 other scrappers in the area (or more), well at least I would, so many people doing it. That said, I only hit areas where general trash can be set out every week, meaning washers, dryers, fridges, household trash, lone bags of trash, etc. My neighborhood for example issues a single trash can, and you can fill that up, once it is full, you are out of luck until the following week. But we have a bulk collection service you have to schedule to pick up trash, meaning it is hard to gauge when you'll see appliances or cleanouts, so not worth the time wasting gas around here. I then of course aim for neighborhoods that steadily yield decent pickups, learn this over a bit of time, and yes there are specific areas I find better than others.