Shorten simple finds considerably and improve readability by using the dynamic find_all_by and find_by methods.
No need to pass foreign keys in find conditions, just do the find through a has_many association.
Learn how to use with_scope - a very powerful method which will allow your custom find methods to accept any find options. Just like magic!
Did you know ActiveRecord provides class methods for performing calculations on models? You can even use these methods through associations.
You can pass more than simple strings to find conditions. Arrays, ranges, and nil values can be passed as well. In this episode you will see the tricks involved with passing these odd objects to find conditions. (Update: audio fixed).
Have you ever wanted to temporarily disable all validations? Well, ActiveRecord doesn't support this, but that doesn't mean we can't add it. This episode will show you how to open up an existing class and change its behavior.