There are two main ways to trap errors in VLOOKUP and other lookup functions in Excel:

1. IFERROR Function:

- This function allows you to define what you want Excel to display if an error occurs in the lookup function.

Example with VLOOKUP:

```excel
=IFERROR(VLOOKUP(lookup_value, table_array, col_index_num, is_sorted), "Error: Value Not Found")
```

- In this example, if the VLOOKUP function doesn't find a match, "Error: Value Not Found" will be displayed instead of the #N/A error. You can customize the message to anything you like.

2. ISNA Function (or other error checking functions):

- You can combine the lookup function with the ISNA function (checks for #N/A error) or other error checking functions (e.g., ISERR for any error) to perform a specific action based on the error type.

Example with VLOOKUP and ISNA:

```excel
=IF(ISNA(VLOOKUP(lookup_value, table_array, col_index_num, is_sorted)), "", VLOOKUP(lookup_value, table_array, col_index_num, is_sorted))
```

- Here, if VLOOKUP encounters an error, an empty string ("") is displayed. You can choose a different output based on your needs.

Additional Tips:

* You can nest these functions for more complex error handling scenarios.
* Consider using INDEX/MATCH instead of VLOOKUP if you need more flexibility in your lookups, especially when the lookup value isn't in the first column of the table.
* Remember to adjust the lookup_value, table_array, col_index_num, and is_sorted arguments according to your specific VLOOKUP formula.

By implementing these techniques, you can make your spreadsheets more user-friendly and avoid misleading #N/A errors.