Sure, here is how you can use the IF function to conditionally format cells based on certain criteria in Excel:

Conditional formatting with IF function

1. Set up your data. In this example, we'll use a list of sample sales data.

2. Create a conditional formatting rule based on the IF function. Here, we want to highlight cells that exceed a target sales amount of $100.

- Select the cells you want to apply the conditional formatting to (in this case, your sales data range).
- Go to the Home tab and click on Conditional Formatting in the Styles group.
- Select New Rule... from the dropdown menu.

3. In the New Formatting Rule window, choose Use a formula to determine which cells to format.

4. Enter the following formula in the Format values where this formula is true field:

```excel
=IF(A1>100,TRUE,FALSE)
```

- Replace A1 with the actual cell reference of your first data cell. The formula uses the IF function to check if the value in the cell is greater than 100. If true, it returns TRUE; otherwise, it returns FALSE.

5. Click Format to set the formatting style for cells that meet the criteria (e.g., fill color, font color, etc.).

6. Click OK to apply the conditional formatting rule.

Now, any cells with sales figures exceeding $100 will be highlighted with the formatting you applied.

Additional Notes:

* You can adjust the formula based on your specific criteria. For example, to highlight cells below a certain value, you can use the following formula:

```excel
=IF(A1<50,TRUE,FALSE)
```

* You can also use more complex logical operators (AND, OR, NOT) within the IF function to create more intricate conditional formatting rules.

By using the IF function in conditional formatting, you can automate the process of highlighting important data points in your Excel spreadsheet, making it easier to identify trends and patterns.