There’s a company called Learn OmniFocus which does lots of video training and for what I’m sure is an entirely affordable and good price if I could ever get around to looking into that. Their latest video, though, is free. Yes, it’s promoting the service as a whole but it’s not doing so by leaving you with a cliffhanger.
Take a look at this video advice on how to use the superb OmniFocus To Do software in conjuction with your email. To the advantage of all humanity.