Spreadsheet features people find years too late, ranked by how much time they give back

Asked around for the thing people discovered embarrassingly late. Sorted by how much it actually saves, not how clever it is.

• Select to the end of a block instead of dragging. Ctrl with an arrow jumps to the edge of the data; add Shift to select on the way. Dragging through 8,000 rows is the single most common wasted minute.
• Paste special, values only. Ends the entire category of "my formula broke when I moved it".
• Turn a range into a table. Formulas then refer to column names, new rows inherit everything automatically, and the range stops needing to be re-selected every time the data grows.
• Name your ranges. A formula that says tax rate rather than a cell address is readable in six months, and moving the cell no longer breaks anything.
• Freeze panes, and split the window. Two views of the same sheet, so you stop scrolling up to check a header.
• The camera or linked-picture tool. A live image of another range, which is how people build one-page summaries without copying data around.
• Flash fill. Type the result you want twice and it infers the pattern. Replaces most of the string formulas people write once and never understand again.
• Fix a reference with F4 while typing, rather than adding the dollar signs by hand.

The pattern worth noticing: almost all of these remove a manual step you repeat, rather than making one calculation cleverer. That is where the time actually is.