The array formula is a wonderful thing in Google Sheets, in most cases providing the opportunity to enter just the one formula and have it automatically fill down as new entries appear from elsewhere.

A clever trick though is to create an array within an array, which allows for header rows to be included.

Here is a normal array formula, which you would normally have to put in row 2, and write in a header above it.

However if you put everything in curly braces, and a  text at the beginning, you can put the formula in row 1, and a header magically appears with the arrayformula below it.

Even better, if you work with awesome tables, and need that second header row to define column filters, you can add that too