This is one of those tips that may elicit an 'ahhhh', if you haven't used Conditional Formatting before.

Conditional Formatting is an option under Format that provides the ability to control the font and cell attributes.  You can programmatically control the font - style, size, color, and/or the cell - color, border and pattern.  Conditional Formatting can respond to the contents of a cell, or the 'TRUE' result of a formula, and provides the ability to logically 'OR' three conditions.

Here's an example that shows when the Quarterly revenues are >= 30% of the Total, by making the font Green (Bold) and when the Quarterly revenue is <=20 of the Total by making the font Red (Bold).

Here are a couple of unique applications.  The level of the Gauge on the left rises or falls as the spinner control is held up, or down.  The Chart on the right is not a graph - the columns are filled by conditional formatting in response to the inputs for each Qx Actual.

If you would like to experiment with Conditional Formatting using these Excel examples, click here to request the Excel: Conditional Formatting Demo and I will send you the file.