Do you avoid "Data Junk" (data not manually entered by yourself)?

When there are too many choices always Default to the most common ones. Then add a checkbox to allow the advanced users to turn off the common choices.

Likewise in a contacts database where you have entries from all around the world it is good to add a check box on the search screen similar to the following:

A good example on that the checkbox on the search screen of TimePRO.NET:

Read our rule on Validation - Do you avoid capturing incorrect data?