The same fifteen categories dominate margin at estate sales. Learn them, and your route through a house changes.
Glass and dishware
Pyrex by pattern (especially pattern numbers on the bottom) — the small early patterns are worth checking sold-comps on every single time. Fenton and carnival glass. marked Mikasa. Signed Royal Doulton and Rainbow Art Glass reach collector prices.
Furniture era targets
Mid-century modern by named designers gets comp'd on eBay or Chairish prices like crazy. Danish Modern especially. Shaker and Mission-era pieces vary widely by region. Bassett and Heywood-Wakefield have dedicated followings.
Signed stuff
Anything with a signature you can verify — fine art, ceramics, woodwork. Bring a spreadsheet of known local makers. Estate jewelry with provenance or legit gemstones commands serious prices.
Tools and shop goods
Vintage hand planes, Stuttgart branded tools, complete tap-and-die sets. Buy when clean, clean-out pricing is commonly 40% of retail.
Paper
First-edition books with intact dust jackets, sheet music, pre-war comic books, local ephemera. Condition rules here more than anywhere.
The didn't-make-the-list but sell-anyway
Magazines from decades ago, vintage trailers and campers, tractor implements, sports pennants, hand-forged farm tools. The most important part is the sale description: categories listed in the listing text like "Patio Furniture, Antiques, and Collectibles" tell you whether the house is worth the drive before you leave home.