Double Clicking in a cell to take you directly to the source of data of the formula is possibly one of the most useful tricks available when working with a spreadsheet with multiple worksheets and many formulae.
In the example below there is a formula in cell D2 which references somewhere else in the workbook. By Double Clicking the cell it will take you to the source of the formula.
Double Clicking the cell not only takes you to the cell, but in this case it also highlights the cells that are included within the SUM formula.
As you can imagine when you have a spreadsheet with multiple tabs and formulae this is a very quick and easy way to navigate around your spreadsheet and it also saves you having to remember the formula.
To enable this functionality you need to change one setting in the Excel Advanced Options Section. To do this:
Select File then Options
Then Advanced and then make sure that Allow editing directly in cells is unchecked.