Checking Nulls

This is my very first blog. In order to keep it simple I am just giving a tip for the new developers who are eager to complete the code but might overlook a very simple yet annoying issue.
Most of the time during coding we fail to address the NULL exceptions. This will be 80% of the time. In order to avoid this we need to make sure that the field we are working on if its from database is NOT null in case its a "nullable" field in the db.
Similarly, we need to check if a "QueryString", "Variable", "Session" , "DataSet", "Table" and so on are not NULL before we start working on it. This will reduce 70% of the issues during testing.