One thing I have found out useful is having a setup where you can easily write test cases for ORM queries using a real database and see a log file of generated

One thing I have found out useful is having a setup where you can easily write test cases for ORM queries using a real database and see a log file of generated SQL. Most of the "strange ORM errors" are much easier to figure out when you can see the DDL (like foreign keys) and the queries/updates that ORM is generating.