Estate Sales can be fun...though some people take them very seriously. If you really want to get the "good stuff" you have to be there before the doors open, and get on the wait list for entering. That requires something like a 6:00 a.m. departure from the house, IF the sale is near you. If you are able to do that, then you can get first pick of all the items in the sale.
People who take Estate Sales seriously follow the above guidelines; however, I have found that the early birds are generally re-sellers, who buy items inexpensively at estate sales, and then re-sell them online for a higher price. It's a business for them.
I don't take Estate Sales seriously. I generally wander in much after the sale has begun and just browse. China is never an in demand item for causal estate salers, so I can sometimes find a few treasures as I did on this day. However, fine china can have a nice resale value, so by the time I saunter in, most of the best stuff has gone to the early birds.
One thing I do anytime before I visit a sale, however, is that I check out the online estate sale site, just to get a feel for what is available for purchase. Generally, Estate Sales take pictures of items for purchase, so you can see what is inside the house before you visit. Some estate sales, for example, have loads of tools, or collections of dolls, or trains!...I'm not interested in those kinds of things...but lots of people are. And to each her own.
If you want to see what kind of estate sales are in your area, just to check it out and browse around (you don't have to buy anything!) -- here's the best site to use:
Click on the link, put in your zip code and it will tell you what estate sales are coming up in your area!