Readability is key point in unit tests. One common antipattern with unit tests are setup methods, because they make unit tests more difficult to read. Here I have written how helper methods can be used instead of setup methods to make unit tests more readable.
This is something that has made my integration tests better. You define a test method to run in transaction and rollback at the end of each test. This makes it possible to write integration tests that write to the database. And tests won't leave any "garbage" there because rollback at the end of the test undoes all database updates (and inserts and deletes). If this is possible in your language and testing framework I strongly recommend it. In this blog post I will explain how you can do it with NUnit in C#.