One of the best ways to counter errors is to catch them at design time,stopping them before they start.
Option Explicit - Forces explicit declaration of all variables at module level, when used. Its declaration must appear in the module before any procedures.
Option Strict - VB generally allows conversions of data from one data type to another without any problem. However, if the results of the conversion is loss of data, then your application will throw an exception. The use of Option Strict will prevent you from making such errors.