Best practice for managing depths in 2d development?

I've started using Unity for 2d development and I've had some frustrations getting all my sprites to have the correct z values so that they are ordered properly. Is their a plugin or some best practices that are commonly used to manage depth? I'm used to 2d game engines like Corona where all you care about is the depth order of an object, as opposed to a specific z value, so it makes it easy to bring an object to the front or the back of a group.