While those are usually rectangular, he specifically likes the 1.25-inch square-cube ice—the best for solidity, stackability and shaker-friendliness. Bonus if they’re clear, of course.

Ice-cube trays came on the scene in the early 1900s, but the square tray we all know and mildly resent became widespread in the 1930s and ’40s. This flexible, all-metal tray with 14 square holes ...