Templates and refining templates is key.
But I would also suggest having multiple autoresponders set up for multiple purposes so that you have content going out for months and even years in advance. It's not exactly set it and forget, but it's a great feeling to know that things are going out into the world and moving even when you're taking a much needed break.
Likewise, you can spend one day and have a whole month's worth (or more) of blogposts set to go out automatically, leaving you free to work on content.
If you're happy to use gmail and holiday response, you can work some magic that way to for various purposes.
Then there's just the traffic getting processes of having YouTube content and the like. It's not necessarily going to get a lot of heat, but I'm still getting subscribes from videos I made three years ago and all of that builds up over time.
And where preparation meets opportunity, there is no ceiling. One of the best pieces of advice I ever heard, and having lots of processes running is one way to help that happen.
