Where do you look for rare records and pressings ?

Most of us that have collections built over decades have some simple rules, like buy it where you can... and never pass up the one you want, as you may never see it again.
There is no easy to flip switch that makes for ease in getting to a bigger collection. If there was, we'd have all marched through that door ourselves.

You gotta work at it. For a long time. No shortcuts except that of money.

Yeah, chase never ends. Since I don't need many records I have an advantage when it comes to the price, within reason. Couple of records a year is fine. Trusted dealers is a good idea, those that kind of accept special orders.
By the way, I ignore amazon as much as I can, it is a monster company closely aligned with the government, not the best part of the government. I don't care what they got.

Yard sales pretty much dried up around here in N. Va twenty years ago, after a rapid decent. And it used to be so great for a long time, maybe the best in the country. I could hit fifty yard sales a day on a good day. Maybe it’s all the recessions, but now it’s only dirty baby diapers. eBay is the final frontier.

I did get a few from Japan on ebay but that's it and I can't check ebay every hour in an effort not to miss anything. Same with discogs. We just need more upscale vintage boutique stores, not only for records. I liked ebay much more in the beginning when there was no buy it now, only auctions. It was a little wild and sometimes you had to send cash. No problem for me, I lost some but gained more. And there was virtually no overgrading, in my experience, and Japanese usually downgraded.

Discogs, WFMU's annual record sale (though I've only been once since I live on the west coast). I'm also fortunate enough to live near several excellent record stores.