Recommended Error Strategies?

Thanks! Yes, unfortunately we don't have good documentation around this for the iOS Core SDK. (If you're just starting out and can use Swift though, you may want to use the Dropbox SwiftyDropbox SDK instead, which has better documentation and more explicit error handling.) 

Anyway, it sounds like you've already handled sessionDidReceiveAuthorizationFailure on DBSession. That covers authorization failures. 

For other errors, you should make sure to implement the error callbacks for whatever methods you're using. You can find the full list in DBRestClient.h, along with some more comments about them.