I have a palette of bricks of known color to calibrate against. If you've got a good number of sets, you'll likely start to accumulate things that are only in a few colors. If possible, it's nice to switch those up with a 1x2 brick in that color for consistency and because the 1x2s are stable on the large area maps.

> As an example, here the description of a brick I struggled to name. I've since figured it out, but you are welcome to guess: flat 4x1 with bumps only on the ends (yes, "bumps", because I don't know what the technical term is. Again, I'm sure there's a guide or glossary I could find.)

You kind of work up to it. There are very small and hard to read numbers on a lot of the parts that helps sometimes. Searching for 1x4, ignore printed parts, shows 230 parts on rebrickable (other sites may vary), looking through all those pictures gets me to "Plate Special 1 x 4 with 2 Studs" [1]. I don't think there's a brick like this, or I can't find it, just the plate; but then you didn't know the magic terminology that the flat pieces (1/3rd height) are plates, not bricks. Had I properly interpreted your description, I'd have jumped to the plates, special category, and skipped the search.

[1] https://rebrickable.com/parts/92593/plate-special-1-x-4-with...

Judging by the 623 answered questions with the "part-identification" tag (out of 636)[0], I'd say pretty open. A lot of them are just what you are asking for, people helping IDing a single part from a picture. Some are much more specific, asking about minor variations on parts, and still get a detailed answer a lot of the time.

[0]https://bricks.stackexchange.com/questions/tagged/part-ident...