You’ll either slap your head out of amazement or because this tip is so trivial. Ever get to the end of an Audible book and you don’t have a new one ready to go? On iOS, you can’t just purchase another book right there in the Audible app.
If you’re a hardened nerd, you have 1Password installed. Jump over there and open the Audible web page. Buy a new book and then jump back to the Audible app. Refresh the cloud library and then start downloading the new book. Ding!