Don’t pass an object into a method if all you really need are some of its property values. Say you have a Customer object with properties like FirstName, LastName, EmailAddress, etc… If all you really need are just a few of those property values, then pass in those individual values instead of passing in the object itself. A method with a signature like DoSomething(string firstName, string lastName, string emailAddress) is easier to maintain and write tests for, than something like DoSomething(Customer customer).

Dino Bansigan @Dino